PinoyBIX Engineering Problem Solving & Reference

This is 100 items set of Practice Examination 1 in General Engineering and Applied Sciences (GEAS) composed of previous Board Exams Questions and/or from related books and resources. Read each questions and choices carefully! Choose the best answer. In the actual board, you have to answer 100 items in General Engineering and Applied Sciences within 5 hours. You have to get at least 70% to pass the subject. General Engineering and Applied Sciences is 20% of the total 100% Board Rating along with Mathematics (20%), Communications Engineering (30%) and Electronics Engineering (30%). Familiarize each and every questions to increase the chance of passing the ECE Board Examination.

Start the Test Yourself Exam 1

Choose the letter of the best answer in each questions.

1. A hunter takes an aim at a monkey sitting on a tree and fires a bullet. Just when the bullet leaves the barrel of the gun, it so happens that the monkey begins to fall freely. The bullet will

• A. go above the monkey
• B. go below the monkey
• C. may or may not hit the monkey. It will depend upon the velocity of the bullet
• D. hit the monkey

ANS: D

2. Two anti-aircraft guns fire two shells, one at an angle of 20° with the horizontal and the other at an angle of 70° with the horizontal. If muzzle velocity is same in both the cases, then

• A. the first shell has a smaller horizontal range
• B. the second shell has a smaller horizontal range
• C. both the shells have the same vertical range
• D. both the shells have the same horizontal range

ANS: D

3. Particles that most affects material properties.

• A. Neutrons
• B. Protons
• C. Electrons
• D. Valence electrons

ANS: D

4. A heavy uniform chain lies on a horizontal table top. If the coefficient of friction between the chain and the table is 0.25, then the maximum percentage of the length of the chain that can hang over one edge of the table is

• A. 20%
• B. 25%
• C. 35%
• D. 15%

ANS: A

5. The figure below shows system of three masses being pulled with a force F. The masses are connected to each other by strings. The horizontal surface is frictionless. The tension T₁ in the first string is 16 N. The acceleration of the system is

• A. m
• B. 2 / m
• C. 3 / m
• D. 4 / m

ANS: B

6. There are atomic clocks capable of measuring time with an accuracy of 1 part in 10¹¹. If two such clocks are operated with precision, then after running for 5000 years, these will record

• A. a difference of nearly 1 s
• B. a difference of 1 day
• C. a difference of 10¹¹
• D. a difference of 1 year

ANS: A

7. Which one of the following is not a strong bond?

• A. van der Waals bond
• B. Covalent bond
• C. Metallic bond
• D. Ionic bond

ANS: A

8. A projectile is projected with kinetic energy of 800 J. If it has the maximum possible horizontal range, then its kinetic energy at the highest point will be

• A. 800 J
• B. 400 J
• C. 200 J
• D. 100 J

ANS: B

9. If the air resistance causes a vertical retardation of 10% of value of acceleration due to gravity, then the time of flight of an oblique projectile will be decreased by nearly

• A. 6%
• B. 7%
• C. 8%
• D. 9%

ANS: D

10. A projectile A is thrown at an angle of 30° to the horizontal from point P. At the same time, another projectile B is thrown with velocity v₂ upwards from the point Q vertically below the highest point. For B to collide with A, v₂/v₁ should be

• A. 1
• B. 2
• C. ½
• D. 4

ANS: C

11. If a material is subjected to two incremental true strains namely ε₁ and ε₂, then the total true strain is

• A. ε₁ x ε₂
• B. ε₁ - ε₂
• C. ε₁ + ε₂
• D. ε₁/ε₂

ANS: C

12. The boundary line between (liquid) and (liquid + solid) regions must be part of

• A. Solvus
• B. Solidus
• C. Liquidus
• D. Tie-line

ANS: C

13. A perfectly reversible heat pump with a coefficient of performance of 14 supplies energy to a building as heat to maintain its temperature at 27°C. If the pump motor does work at the rate of 1 kW, at what rate does the pump supply energy to the building as heat?

• A. 15 kW
• B. 3.85 kW
• C. 1.35 kW
• D. 1.07 Kw

ANS: A

14. A machine gun mounted on a 2000 kg car on a horizontal frictionless surface fire 10 bullets per second. If 10 g be the mass of each bullet and 500 m/s the velocity of each bullet, then the acceleration of the car will be

• A. 1/10 ms^-2
• B. 1/20 ms^-2
• C. 1/40 ms^-2
• D. 1/60 ms^-2

ANS: C

15. A heat engine operates between 200 K and 100 K. In each cycle it takes 100 J from the hot reservoir, loses 25 J to the cold reservoir, and does 75 J of work. This heat engine violates

• A. both the first and second laws of thermodynamics
• B. the first law but not the second law of thermodynamics
• C. the second law but not the first law of thermodynamics
• D. neither the first law nor the second law of thermodynamics

ANS: C

16. Mean distance between atoms in the range of

• A. 25 nm
• B. 2.5 nm
• C. 0.25 nm
• D. 0.025 nm

ANS: C

17. Octane, a component of gasoline, has eight carbon atoms and eighteen hydrogen atoms per molecule. Its formula is written as

• A. C₁₈H₈
• B. C₈H₁₈
• C. C₈H₁₈
• D. C₄H₉

ANS: C

18. The boundary line between (alpha) and (alpha + beta) regions must be part of

• A. Solvus
• B. Solidus
• C. Liquidus
• D. Tie-line

ANS: A

19. A method of computing depreciation in which the annual charge is a fixed percentage of the depreciated book value at the beginning of the year to which the depreciation applies.

• A. straight
• B. sinking fund
• C. sum of-the year’s digit
• D. declining balance

ANS: D

20. The approximate value of g at an altitude above Earth equal to one Earth diameter is

• A. 9.8 m/s²
• B. 4.9 m/s²
• C. 2.5 m/s²
• D. 1.1 m/s²

ANS: D

21. Bromine, with atomic mass 79.942 u, is composed of nearly equal amounts of two isotopes, one of which contains 79 nucleons per atom. The mass number of the other isotope is

• A. 78
• B. 79
• C. 80
• D. 81

ANS: D

22. Water flows through a cylindrical pipe of varying cross section. The velocity is 3.0 m/s at a point where the pipe diameter is 1.0 cm. At a point where the pipe diameter is 3.0 cm, the velocity is

• A. 9 m/s
• B. 3 m/s
• C. 1 m/s
• D. 0.33 m/s

ANS: D

23. A 5.0-kg crate is on an incline that makes an angle of 30° with the horizontal. If the coefficient of static friction is 0.5, the maximum force that can be applied parallel to the plane without moving the crate is

• A. 0
• B. 3.3 N
• C. 30 N
• D. 46 N

ANS: D

24. The profit derived from a project or business enterprise without consideration of obligations to financial contributors or claims of other based on profit.

• A. economic return
• B. yield
• C. earning value
• D. expected yield

ANS: A

25. A cube with edges exactly 2 cm long is made of material with a bulk modulus of 3.5 × 10⁹ N/m². When it is subjected to a pressure of 3.0 × 10⁵ Pa its volume is

• A. 7.31 cm³
• B. 7.99931 cm³
• C. 8.00069 cm³
• D. 8.69 cm³

ANS: B

26. Block A, with mass m_A, is initially at rest on a horizontal floor. Block B, with mass m_B, is initially at rest on the horizontal top surface of A. The coefficient of static friction between the two blocks is µ_s. Block A is pulled with a horizontal force. It begins to slide out from under B if the force is greater than:

• A. m_Ag
• B. m_Bg
• C. µ_sm_Ag
• D. µ_s (m_A +m_B)g

ANS: D

27. A distinct legal entity which can practically transact any business transaction which a real person could do.

• A. sole proprietorship
• B. enterprise
• C. partnership
• D. corporation

ANS: D

28. An example of an inertial reference frame is

• A. any reference frame that is not accelerating
• B. a frame attached to a particle on which there are no forces
• C. any reference frame that is at rest
• D. a reference frame attached to the center of the universe

ANS: B

29. An object moving in a circle at constant speed

• A. must have only one force acting on it
• B. is not accelerating
• C. is held to its path by centrifugal force
• D. has an acceleration of constant magnitude

ANS: D

30. The boundary line between (liquid + solid) and (solid) regions must be part of

• A. Solvus
• B. Solidus
• C. Liquidus
• D. Tie-line

ANS: B

31. A 50-N force is the only force on a 2-kg object that starts from rest. When the force has been acting for 2-s the rate at which it is doing work is

• A. 75 W
• B. 100 W
• C. 1000 W
• D. 2500 W

ANS: D

32. A disk is free to rotate on a fixed axis. A force of given magnitude F, in the plane of the disk, is to be applied. Of the following alternatives the greatest angular acceleration is obtained if the force is

• A. applied tangentially halfway between the axis and the rim
• B. applied tangentially at the rim
• C. applied radially halfway between the axis and the rim
• D. applied radially at the rim

ANS: B

33. A cylinder is 0.10 m in radius and 0.20 m in length. Its rotational inertia, about the cylinder axis on which it is mounted, is 0.020 kg · m². A string is wound around the cylinder and pulled with a force of 1.0 N. The angular acceleration of the cylinder is

• A. 2.5 rad/s²
• B. 5.0 rad/s²
• C. 10 rad/s²
• D. 15 rad/s²

ANS: B

34. Figure-out the odd point in the following

• A. Proportional limit
• B. Elastic limit
• C. Yield point
• D. Fracture point

ANS: D

35. Two supports, made of the same material and initially of equal length, are 2.0 m apart. A stiff board with a length of 4.0 m and a mass of 10 kg is placed on the supports, with one support at the left end and the other at the midpoint. A block is placed on the board a distance of 0.50 m from the left end. As a result the board is horizontal. The mass of the block is

• A. zero
• B. 2.3 kg
• C. 6.6 kg
• D. 20 kg

ANS: D

36. The bulk modulus is a proportionality constant that relates the pressure acting on an object to

• A. the shear
• B. the fractional change in volume
• C. the fractional change in length
• D. Young’s modulus

ANS: B

37. Fahrenheit and Kelvin scales agree numerically at a reading of

• A. -40
• B. 0
• C. 273
• D. 574

ANS: D

38. If the molecules in a tank of hydrogen have the same rms speed as the molecules in a tank of oxygen, we may be sure that

• A. the pressures are the same
• B. the hydrogen is at the higher temperature
• C. the hydrogen is at the greater pressure
• D. the oxygen is at the higher temperature

ANS: D

39. Capitalized cost of any structure or property is equal to

• A. first cost + interest
• B. annual cost of the first cost
• C. first cost + cost of perpetual maintenance, operation and replacement
• D. first cost + salvage value

ANS: C

40. A 40-cm long string, with one end clamped and the other free to move transversely, is vibrating in its fundamental standing wave mode. The wavelength of the constituent travelling waves is

• A. 10 cm
• B. 20 cm
• C. 40 cm
• D. 160 cm

ANS: D

41. A sample of argon gas (molar mass 40 g) is at four times the absolute temperature of a sample of hydrogen gas (molar mass 2 g). The ratio of the rms speed of the argon molecules to that of the hydrogen is

• A. 1
• B. 5
• C. 1/5
• D. √5

ANS: D

42. The rotational inertia of a solid uniform sphere about a diameter is 2/5 MR², where M is its mass and R is its radius. If the sphere is pivoted about an axis that is tangent to its surface, its rotational inertia is:

• A. MR²
• B. 2/5 MR²
• C. 3/5 MR²
• D. 7/5 MR²

ANS: D

43. Young’s modulus is a proportionality constant that relates the force per unit area applied perpendicularly at the surface of an object to

• A. the shear
• B. the fractional change in volume
• C. the fractional change in length
• D. the pressure

ANS: C

44. One piston in a hydraulic lift has an area that is twice the area of the other. When the pressure at the smaller piston is increased by Δp the pressure at the larger piston

• A. increases by 2Δp
• B. increases by Δp/2
• C. increases by Δp
• D. increases by 4Δp

ANS: C

45. An insulated container, filled with water, contains a thermometer and a paddle wheel. The paddle wheel can be rotated by an external source. This apparatus can be used to determine

• A. specific heat of water
• B. relation between kinetic energy and absolute temperature
• C. efficiency of changing work into heat
• D. mechanical equivalent of heat

ANS: D

46. If two objects are in thermal equilibrium with each other:

• A. they cannot be moving
• B. they cannot be undergoing an elastic collision
• C. they cannot have different pressures
• D. they cannot be at different temperatures

ANS: D

47. Take the mechanical equivalent of heat as 4 J/cal. A 10-g bullet moving at 2000 m/s plunges into 1 kg of paraffin wax (specific heat 0.7 cal/g·C°). The wax was initially at 20° C. Assuming that all the bullet’s energy heats the wax, its final temperature (in °C) is

• A. 20.14
• B. 23.5
• C. 20.006
• D. 27.1

ANS: D

48. The flow back of profit plus depreciation from a given project is called

• A. capital recovery
• B. cash flow
• C. economic return
• D. earning value

ANS: B

49. A stone is tied to a string and whirled at constant speed in a horizontal circle. The speed is then doubled without changing the length of the string. Afterward the magnitude of the acceleration of the stone is:

• A. the same
• B. twice as great
• C. four times as great
• D. half as great

ANS: C

50. A disk with a rotational inertia of 5.0 kg·m² and a radius of 0.25 m rotates on a fixed axis perpendicular to the disk and through its center. A force of 2.0 N is applied tangentially to the rim. As the disk turns through half a revolution the work done by the force is

• A. 1.6 J
• B. 2.5 J
• C. 6.3 J
• D. 10 J

ANS: A

51. Ideal monatomic gas A is composed of molecules with mass m while ideal monatomic gas B is composed of molecules with mass 4 m. The average translational kinetic energies are the same if the ratio of the temperatures T_A/T_B is:

• A. ¼
• B. ½
• C. 1
• D. 2

ANS: C

52. A projectile is fired from ground level over level ground with an initial velocity that has a vertical component of 20 m/s and a horizontal component of 30 m/s. Using g = 10 m/s², the distance from launching to landing points is

• A. 40 m
• B. 60 m
• C. 80 m
• D. 120 m

ANS: D

53. The recorded current value of an asset is known as

• A. scrap value
• B. salvage value
• C. book value
• D. present worth

ANS: C

54. A ball with a weight of 1.5 N is thrown at an angle of 30° above the horizontal with an initial speed of 12 m/s. At its highest point, the net force on the ball is

• A. 9.8 N, 30° below horizontal
• B. zero
• C. 9.8 N, up
• D. 1.5 N, down

ANS: D

55. String is wrapped around the periphery of a 5.0-cm radius cylinder, free to rotate on its axis. The string is pulled straight out at a constant rate of 10 cm/s and does not slip on the cylinder. As each small segment of string leaves the cylinder, its acceleration changes by:

• A. 0
• B. 0.010 m/s²
• C. 0.020 m/s²
• D. 0.20 m/s²

ANS: D

56. A flywheel of diameter 1.2 m has a constant angular acceleration of 5.0 rad/s². The tangential acceleration of a point on its rim is:

• A. 5.0 rad/s²
• B. 3.0 m/s²
• C. 5.0 m/s²
• D. 3.0 rad/s²

ANS: B

57. A playground merry-go-round has a radius of 3.0 m and a rotational inertia of 600 kg·m². It is initially spinning at 0.80 rad/s when a 20-kg child crawls from the center to the rim. When the child reaches the rim the angular velocity of the merry-go-round is:

• A. 0.62 rad/s
• B. 0.73 rad/s
• C. 0.80 rad/s
• D. 0.89 rad/s

ANS: A

58. When two gases separated by a diathermal wall are in thermal equilibrium with each other:

• A. only their pressures must be the same
• B. only their volumes must be the same
• C. they must have the same number of particles
• D. only their temperatures must be the same

ANS: D

59. A balloon is filled with cold air and placed in a warm room. It is NOT in thermal equilibrium with the air of the room until:

• A. it rises to the ceiling
• B. it sinks to the floor
• C. it stops expanding
• D. it starts to contract

ANS: C

60. During a slow adiabatic expansion of a gas:

• A. the pressure remains constant
• B. energy is added as heat
• C. work is done on the gas
• D. no energy enters or leaves as heat

ANS: D

61. Two objects with masses of m₁ and m₂ have the same kinetic energy and are both moving to the right. The same constant force F is applied to the left to both masses. If m₁ = 4m₂, the ratio of the stopping distance of m₁ to that of m₂ is:

• A. 1:4
• B. 4:1
• C. 1:2
• D. 1:1

ANS: D

62. A stone is released from rest from the edge of a building roof 190 m above the ground. Neglecting air resistance, the speed of the stone, just before striking the ground, is

• A. 43 m/s
• B. 61 m/s
• C. 120 m/s
• D. 190 m/s

ANS: B

63. A man weighing 700 Nb is in an elevator that is accelerating upward at 4 m/s². The force exerted on him by the elevator floor is

• A. 71 N
• B. 290 N
• C. 410 N
• D. 990 N

ANS: D

64. The lessening of the value of an asset due to the decrease in the quantity available (referring to the natural resources, coal, etc.)

• A. depreciation
• B. depletion
• C. inflation
• D. incremental cost

ANS: B

65. A cube of aluminum has an edge length of 20 cm. Aluminum has a density 2.7 times that of water (1 g/cm³) and a specific heat 0.217 times that of water (1 cal/g·C°). When the internal energy of the cube increases by 47000 cal its temperature increases by

• A. 5 C°
• B. 10 C°
• C. 20 C°
• D. 100 C°

ANS: B

66. A Carnot heat engine and an irreversible heat engine both operate between the same high temperature and low temperature reservoirs. They absorb the same energy from the high temperature reservoir as heat. The irreversible engine

• A. does more work
• B. transfers more energy to the low temperature reservoir as heat
• C. has the greater efficiency
• D. has the same efficiency as the reversible engine

ANS: B

67. Glycine, one of the essential amino acids, has two carbon atoms, five hydrogen atoms, two oxygen atoms, and one nitrogen atom per molecule. Its formula is written as

• A. C₂H₅NO₂
• B. Ca₂H₅NO₂
• C. C₂H₅NeO₂
• D. CHNO₂

ANS: A

68. Some common ions based on Group 1A or alkali metal elements are

• A. Na⁺, Ca²⁺, Fe³⁺
• B. Na⁺, Li⁺, Cs⁺
• C. Li⁺, Ag⁺, Au⁺
• D. Ca²⁺, Ba²⁺, Sr²⁺

ANS: B

69. The molar mass of hydrazine, N₂H₄, is

• A. 4.08 g/mol
• B. 28.00 g/mol
• C. 16.03 g/mol
• D. 32.05 g/mol

ANS: D

70. An association of two or more persons for a purpose of engaging in a profitable business.

• A. sole proprietorship
• B. enterprise
• C. partnership
• D. corporation

ANS: C

71. Transition metals can combine with carbon monoxide (CO) to form compounds such as Fe(CO)₅ and CO₂(CO)₈. Assume that you combine 0.125 g of nickel with CO and isolate 0.364 g of Ni(CO)_x. What is the value of x?

• A. 1
• B. 2
• C. 3
• D. 4

ANS: D

72. A real gas undergoes a process that can be represented as a curve on a p-V diagram. The work done by the gas during this process is:

• A. pV
• B. p(V₂ – V₁)
• C. (p₂ – p₁)V
• D. ∫pdV

ANS: D

73. An inventor claims to have a heat engine that has an efficiency of 40% when it operates between a high temperature reservoir of 150° C and a low temperature reservoir of 30° C. This engine:

• A. must violate the zeroth law of thermodynamics
• B. must violate the first law of thermodynamics
• C. must violate the second law of thermodynamics
• D. must violate the third law of thermodynamics

ANS: C

74. How many grams are there in 1.36 mol of ethyl alcohol, C₂H₆O?

• A. 0.0160 g
• B. 123 g
• C. 62.7 g
• D. 6.27 g

ANS: C

75. What is the name given to the type of a chemical reaction characterized by the release of heat energy?

• A. endothermic
• B. nonspontaneous
• C. exothermic
• D. adiabatic

ANS: C

76. A quantity of an ideal gas is compressed to half its initial volume. The process may be adiabatic, isothermal, or isobaric. Rank those three processes in order of the work required of an external agent, least to greatest.

• A. adiabatic, isothermal, isobaric
• B. adiabatic, isobaric, isothermal
• C. isothermal, adiabatic, isobaric
• D. isobaric, isothermal, adiabatic

ANS: D

77. During a reversible adiabatic expansion of an ideal gas, which of the following is NOT true?

• A. pV^γ = constant
• B. pV = nRT
• C. TV^γ-1 = constant
• D. pV = constant

ANS: D

78. In order that a single process be both isothermal and isobaric:

• A. one must use an ideal gas
• B. such a process is impossible
• C. a change of phase is essential
• D. one may use any real gas such as N₂

ANS: C

79. A condition where only few individual produce a certain product that action of one will lead to almost the same action by the other.

• A. monopoly
• B. oligopoly
• C. semi-monopoly
• D. perfect competition

ANS: B

80. If R is the range for an angle of projection of 15° with the horizontal, then the other angle of projection for which the range is R, is

• A. 75°
• B. 60°
• C. 45°
• D. 30°

ANS: A

81. An object is thrown along a direction inclined at an angle of 45° with the horizontal direction. The horizontal range of the particle is

• A. four times the vertical height
• B. thrice the vertical height
• C. twice the vertical height
• D. equal to vertical height

ANS: A

82. A ball is projected with kinetic energy K at an angle of 45° to the horizontal. At the highest point during its flight, its kinetic energy will be

• A. K
• B. K/√2
• C. K/2
• D. zero

ANS: C

83. Is the simplest form of business organization?

• A. sole proprietorship
• B. partnership
• C. partnership
• D. corporation

ANS: A

84. The enthalpy change is the heat absorbed or given off during a chemical reaction that occurs at constant.

• A. temperature
• B. reaction rate
• C. volume
• D. pressure

ANS: D

85. Two balls are projected from the same point in directions at 30° and 60° with the horizontal. Both the balls attain the same height. The ratio of their velocities of projection is

• A. √3 : 2
• B. √3 : 3
• C. √3 : 5
• D. √3 : 1

ANS: D

86. Citric acid, C₆H₈O₇, is found in many fruits. What is the weight percent of carbon in the compound?

• A. 37.5%
• B. 4.2%
• C. 58.3%
• D. 18.8%

ANS: A

87. A bomb is dropped on an enemy post by an airplane flying horizontally with a velocity of 60 km/h and at a height of 490 m. At the time of dropping the bomb, how far the airplane should be from the enemy post so that the bomb may directly hit the target?

• A. 400/3 m
• B. 500/3 m
• C. 1700/3 m
• D. 250/3 m

ANS: B

88. An airplane flying horizontally with a velocity of 216 km/hr drops a food packet while flying at a height of 490 m. The total horizontal distance travelled by the packet is

• A. 600 m
• B. 490 m
• C. 216 m
• D. 500 m

ANS: A

89. Two bodies of masses m₁ and m₂ are connected by a light, inextensible string which passes over a frictionless pulley. If the pulley is moving upward with uniform acceleration g, then the tension in the string is

• A. (4m₁m₂) / (m₁ + m₂) g
• B. (m₁ + m₂) / (4m₁m₂) g
• C. (m₁m₂) / (m₁ + m₂) g
• D. (m₁ – m₂) / (4m₁ + m₂) g

ANS: A

90. Young’s Modulus is the

• A. ratio of stress to strain
• B. ratio of strain to stress
• C. force per unit area
• D. force per unit elongation

ANS: A

91. The molar mass of vitamin C, C₆H₈O₆, is

• A. 29.02 g/mol
• B. 230.13 g/mol
• C. 176.13 g/mol
• D. 72.00 g/mol

ANS: C

92. Based on everyday experience, which of the following substances has the smallest specific heat capacity, that is, which one heats up most readily?

• A. water
• B. copper
• C. wood
• D. cement

ANS: B

93. A block of mass 1 kg is at rest on a horizontal table. The coefficient of static friction between the block and table is 0.5. If g = 10 m/s², then the magnitude of the force acting upward at an angle of 60° from the horizontal that will just start the block moving is

• A. 5 N
• B. 5.36 N
• C. 74.6 N
• D. 10 N

ANS: B

94. Potassium metal (3.91 g) is allowed to react with excess oxygen (O₂). The reaction yields 7.11 g of an explosive, yellow solid called a “superoxide.” What is the empirical formula of the compound?

• A. KO
• B. KO₂
• C. K₂O
• D. K₂O₃

ANS: B

95. How many moles are contained in 0.206 g of potassium sulfate?

• A. 1.63 x 10^-3 mol
• B. 846 mol
• C. 1.52 x 10^-3 mol
• D. 1.18 x 10^-3 mol

ANS: D

96. If there is a positive error of 50% in the measurement of speed of a body, then the error in the measurement of kinetic energy is

• A. 25%
• B. 50%
• C. 100%
• D. 125%

ANS: D

97. A particle is moving on a circular path with constant speed v. What is the change in its velocity after it has described an angle of 60°?

• A. v√2
• B. v√3
• C. v
• D. 2v

ANS: C

98. A car with a vertical wind shield moves along in a rain storm at speed of 40 km/h. The rain drops fall vertically with a terminal speed of 20 m/s. The angle at which the rain drops strike the wind shield is

• A. tan^-1 (2/3)
• B. tan^-1 (3/2)
• C. tan^-1 (5/9)
• D. tan^-1 (9/5)

ANS: C

99. The center of gravity of a body

• A. must be within the body
• B. may be near but not necessarily within the body
• C. can never be precisely located
• D. changes its position from time to time

ANS: B

100. The acceleration of a body revolving in a circle at uniform speed is

• A. Zero
• B. Directed tangentially
• C. directed toward the center
• D. directed away from the center

ANS: C

Complete List of General Engineering and Applied Sciences Exams: ECE Pre-Board

---

This is 100 items set of Practice Examination 15 in Communications Engineering (Electronics Systems and Technology) composed of previous Board Exams Questions. Read each questions and choices carefully! Choose the best answer. In the actual board, you have to answer 100 items in Communications Engineering within 5 hours. You have to get at least 70% to pass the subject. Communications Engineering is 30% of the total 100% Board Rating along with Mathematics (20%), General Engineering and Applied Sciences (20%) and Electronics Engineering (30%). Familiarize each and every questions to increase the chance of passing the ECE Board Examination.

Start the Test Yourself Exam 15

Choose the letter of the best answer in each questions.

1. Technique employed by wireless infrastructure systems that lowers the power of a signal in a cell site whenever the site detects that the user's phone is close to the source of the signal

• A. Adaptive power control
• B. Pre-emphasis
• C. Level down
• D. Power attenuation

ANS: A

2. A relative range of frequencies that can carry a signal without distortion on a transmission medium

• A. Doppler frequency
• B. Carrier
• C. Bandwidth or pipe
• D. Channel

ANS: C

3. Suppose a TV signal has 10.5 microseconds of horizontal blanking per line and 21 lines of vertical blanking per field. What is the percentage of total time that is occupied by blanking?

• A. 22.92%
• B. 93.22%
• C. 11.45%
• D. 16.67%

ANS: D

4. Estimate the bandwidth occupied by the sound portion of a TV transmission in US.

• A. 25 kHz
• B. 800 kHz
• C. 80 kHz
• D. 200 kHz

ANS: C

5. What is the purpose of using alternate mark inversion and return to zero encoding of data?

• A. faster digital data transmission
• B. assist in clock recovery
• C. more efficient transmission of analog data
• D. reduced susceptibility to noise

ANS: B

6. A measure of the number of subscribers who leave or switch to another carrier's service

• A. Offered traffic
• B. Churn
• C. Carried traffic
• D. Population

ANS: B

7. The power amplifier of an AM transmitter has an output power of 50 W and an efficiency of 60% and is collector modulated. How much audio power is required to be supplied to this stage for 100% modulation?

• A. 833 W
• B. 41.66 W
• C. 30 W
• D. 15 W

ANS: B

8. The old standard unit for measuring the activity of a given radioactive sample which is equivalent to the activity of 1 gram of radium.

• A. Curie
• B. Becquerel
• C. Rad
• D. Rem

ANS: A

9. A combination of two or more integrated circuits on one module

• A. PCB
• B. Combo chip
• C. TTL
• D. Chip set

ANS: D

10. The term applied to a phone that will work on 800 MHz analog, 800 MHz digital and 1900 MHz (also known as 1.9 GHz) frequencies

• A. Tri-mode
• B. Tri Band
• C. Dual Band
• D. Dual-mode

ANS: C

11. A pen-based tablet computer used on a wireless local area network

• A. node
• B. source
• C. thin client
• D. master

ANS: C

12. 1 Petabits is equivalent to how many bits of digital information?

• A. 1 x 1015 bits
• B. 1, 073, 741, 824 bits
• C. 1, 099, 511, 627, 776 bits
• D. 1, 125, 899, 906, 842, 624 bits

ANS: D

13. Where is de-emphasis added in a stereo FM system?

• A. before the matrix at the TX
• B. before the matrix at the R
• C. after the matrix at the TX
• D. after the matrix at the RX

ANS: D

14. How many electron beams actually leave the electron gun of a single-gun color CRT?

• A. 1
• B. 2
• C. 3
• D. 4

ANS: C

15. Determine the quality factor necessary for a single sideband filter with a 1-MHz carrier frequency, 80 dB unwanted suppression and 200-Hz frequency separation.

• A. 15,000
• B. 125,000
• C. 12,000
• D. 25,000

ANS: B

16. A rectangular waveguide has a width of 0.6 inch. Calculate the waveguide cut-off frequency.

• A. 12.84 GHz
• B. 5.84 GHz
• C. 10.84 GHz
• D. 9.84 GHz

ANS: D

17. A permanent-magnet ring on the neck of the tube is used for ________.

• A. scanning
• B. centering
• C. deflecting
• D. focusing

ANS: B

18. The IS-95 CDMA standard developed by Qualcomm Inc

• A. WCDMA
• B. IMT-DS
• C. cdmaOne
• D. IMT-SC

ANS: C

19. The process of creating more coverage and capacity in a geographic area by having more than one cell cover the same area that a single cell originally did

• A. Cell splitting
• B. Frequency reuse
• C. Cell reuse
• D. Cell site

ANS: A

20. Gregorian antenna is consist of

• A. Main paraboloid reflector and an ellipsoid subreflector
• B. Main paraboloid reflector and a hyperboloid subreflector
• C. Main ellipsoid reflector and a hyperboloid subreflector
• D. Main hyperboloid reflector and an ellipsoid subreflector

ANS: A

21. A logic channel carrying network information rather than the actual voice or data messages transmitted over the network

• A. Control channel
• B. Backup channel
• C. Overhead channel
• D. Message channel

ANS: A

22. In which ITU region is Philippines?

• A. ITU Region 1
• B. ITU Region 2
• C. ITU Region 3
• D. ITU Region 4

ANS: C

23. What is the result of over deviation in an FM transmitter?

• A. Increased transmitter range
• B. Increased transmitter power
• C. Poor carrier suppression
• D. Out-of-channel emissions

ANS: D

24. What is the output PEP from a transmitter if an oscilloscope measures 500 volts peak-to-peak across a 50-ohm resistor connected to the transmitter output?

• A. 500 watts
• B. 625 watts
• C. 1250 watts
• D. 2500 watts

ANS: B

25. _________ is the process of impressing or imparting a low frequency source information (voice, audio, video, or data) onto a high-frequency bandpass signal with a carrier frequency fc by the introduction of amplitude, frequency or phase perturbation.

• A. Mixing
• B. Modulation
• C. Heterodyning
• D. Multiplexing

ANS: B

26. A trade group representing cellular, PCS and enhanced specialized mobile radio carriers

• A. CTIA (Cellular Telecommunications Industry Association)
• B. EIA (Electronic Industry Association)
• C. ANSI
• D. SONET

ANS: A

27. Which of the following can cause frequency intermodulation products in a system?

• A. Antenna
• B. Only semiconductor junctions like diodes and transistors (amplifiers)
• C. Cable connectors, bolted or riveted antenna panels, isolators and circulators
• D. Both B and C

ANS: D

28. What type of filter is used in the IF section of receivers to block energy outside a certain frequency range?

• A. An input filter
• B. A low-pass filter
• C. A band-pass filter
• D. A high-pass filter

ANS: C

29. A secret number issued to a cellular phone that is used in conjunction with a subscriber's shared secret data information for authentication

• A. MIN (Mobile Identification Number)
• B. A-key
• C. IMSI (International Mobile Subscriber Identity)
• D. Cipher key

ANS: B

30. A feature on wireless phones where you enter just one or two digits from the keypad and then initiate the call. The phone searches its speed dial directory and associates the entire number with the two-digit speed dial position you've entered.

• A. DTMF dialing
• B. Voice dialing
• C. Pulse dialing
• D. Abbreviated dialing

ANS: D

31. Which of these pairs of materials in the triboelectric series have the greatest charge transfer potential?

• A. Rubber Balloon & Celluloid
• B. Silk & Wool
• C. Metal & Nonmetal
• D. Glass & Hard Rubber

ANS: D

32. A method of taking signal strength measurements in a cellular coverage area

• A. radio sounding
• B. drive test
• C. boresighting
• D. field strength

ANS: B

33. To facilitate frequency planning, ITU divide the world intro three regions. Region 2 includes __________.

• A. North and South America and Greenland
• B. Europe, Africa and Mongolia
• C. Asia Pacific, Australia, and the southwest Pacific
• D. Philippines, and Southeast Asia

ANS: A

34. In satellite communication, what does sun- synchronous means?

• A. They cross the equator at the same local time each month
• B. They cross the equator at the same local time 2x each day
• C. They cross the equator at the same local time each day
• D. They cross the equator at the same local time every 27 days

ANS: C

35. During a network analyzer calibration, why are both a short circuit and an open circuit used?

• A. To determine the power output
• B. To determine the characteristic impedance of the measurement system
• C. Both are easy to produce to at high accuracy
• D. They average to 50 ohms in an RF system

ANS: B

36. At what frequency is electromagnetic energy maximally absorbed due to oxygen in the atmosphere?

• A. 180 GHz
• B. 63 GHz
• C. 22 GHz
• D. 110 GHz

ANS: B

37. The location where the wireless antenna and network communications equipment is placed

• A. Network
• B. Cell site
• C. POP (Point of Presence)
• D. Footprint

ANS: B

38. What does the term "ruggedness" refer to in wireless power amplifiers?

• A. Ability to withstand load mismatch
• B. Ability to withstand thermal stress
• C. Ability to withstand mechanical stress
• D. All the above

ANS: A

39. In which semiconductor technology are the majority of cellphone PAs manufactured?

• A. GaAs/InGaP
• B. GaN
• C. SiGe
• D. Si/SiCMOS

ANS: A

40. What is a major advantage of Low Temperature Co-fired Ceramic (LTCC) substrates?

• A. Better thermal dissipation
• B. Lower bill of materials
• C. Densely integrated passive components
• D. All the above

ANS: D

41. What do you call the center of mass of a two-body system such as the earth and the moon?

• A. orthocentre
• B. barycenter
• C. ethnocenter
• D. geocenter

ANS: B

42. The portion of the wireless system's infrastructure that is responsible for sending and receiving the actual radio signals over the airwaves in a 3G environment

• A. Base station controller
• B. Node B
• C. Gateway
• D. Base transceiver station

ANS: B

43. Spectrum-efficient technology that establishes a queue to handle demand for voice or data channels

• A. Traffic
• B. Multiplexing
• C. Demand Accessing
• D. Trunking

ANS: D

44. A wireless phone programmed with stolen or duplicated electronic serial and mobile identification numbers

• A. RAID
• B. Backup
• C. Clone
• D. Party line

ANS: C

45. A satellite is orbiting the equatorial plane with a period from perigee to perigee of 12 hours. Given the eccentricity is 0.002, calculate the semi-major axis. (Use R_earth = 6378.1414 km)

• A. 25,813 km
• B. 24,781 km
• C. 22,333 km
• D. 26,597 km

ANS: D

46. Fourier analysis often allows complex signals to be express as a series of __________.

• A. sinusoids
• B. pulse
• C. ellipse
• D. rectified signals

ANS: A

47. A geographic area within a wireless system that is covered by the signal sent and received by the transmitter and receiver equipment located within that area

• A. Deadspot
• B. Footprint
• C. Hotspot
• D. Cell

ANS: D

48. Satellite technology to transmit calls from one point on Earth to a satellite and back down to another point

• A. Activetech
• B. Bent pipe technology
• C. Iridium
• D. Global tracking

ANS: B

49. Who is known as ”The Father of Radar?”

• A. Walter Eugene O'Reilly
• B. Albert Einstein
• C. Oliver Heaviside
• D. Robert Watson-Watt

ANS: D

50. Which flying (movement) condition will always result in a Doppler speed of 0 m/s?

• A. Speeds at odd integer multiples of antenna rotation rate
• B. Perfect concentric circle around antenna at constant altitude
• C. Speeds at even integer multiples of antenna rotation rate
• D. Perfectly constant speed into/out of the antenna boresight

ANS: B

51. The technology that enables data connections between electronic devices such as desktop computers, wireless phones, electronic organizers and printers in the 2.4 GHz range

• A. Bluetooth
• B. MMDS (Multipoint Multichannel Distribution system)
• C. LMDS (Local Multipoint Distribution System)
• D. IrDA (Infrared Data Association)

ANS: A

52. Using a wide-bandwidth channel for voice, data and/or video services

• A. Bandwidth
• B. Broadband
• C. Narrowband
• D. Baseband

ANS: B

53. For a parabolic antenna of 3m diameter transmitting a 6-GHz wave has a far field zone that begins at approximately

• A. 7.06 m
• B. 70.6 m
• C. 360 m
• D. 36 m

ANS: C

54. What is the term used for maintaining a satellite in its correct orbital position?

• A. Attitude control
• B. Station keeping
• C. Attitude maneuvering
• D. Spin stabilization

ANS: B

55. Computer systems to help dispatch personnel and vehicles, commonly used by public-safety agencies

• A. Public Address System
• B. Public wireless amplifier
• C. Mobile broadcasting
• D. CAD (computer-aided dispatch)

ANS: D

56. A pager's unique electronic identification number on the back of the device

• A. Back code
• B. Bar code
• C. Cap code
• D. Access Code

ANS: C

57. Find the total number of pixels and the highest video bandwidth of NTSC system television

• A. 75 pixel, 4.27 MHz
• B. 775 pixel, 5.7 MHz
• C. 775 pixel, 4.27 MHz
• D. 575 pixel, 5.7 MHz

ANS: C

58. Telephones, PBXs and other communications devices located in the home or office

• A. Terminal Adapter (TA)
• B. Terminal Equipment (TE)
• C. CPE (Customer Premise Equipment)
• D. MUX (Multiplxer)

ANS: C

59. Slang term for someone who breaks an encrypted computer code or circuitry

• A. Programmer
• B. Cracker
• C. Engineer
• D. Hacker

ANS: B

60. Interference in a wireless communications system that stems from other conversations in nearby cells using the same channel

• A. hits
• B. Intercommunication
• C. Crosstalk
• D. jitter

ANS: C

61. What is the cause of trouble when there is no picture and no sound, with normal raster in a TV receiver?

• A. The trouble must be in the sound circuits, after the sound take-off points
• B. This trouble is in the signal circuits, before the sound take-off point, because both the picture and sounds are affected.
• C. The trouble must be in the vertical deflection oscillator and the vertical output stage
• D. This trouble means the raster and the signal circuits are not operating.

ANS: B

62. Mathematical process that allows complex signals to be express as a series of sinusoids.

• A. Bessel Function
• B. Taylor Series
• C. Fourier analysis
• D. Heaviside Expansion

ANS: C

63. Synthetic Aperture Radar (SAR) radar is mostly likely to be located on which platform?

• A. Airplane
• B. Ship
• C. Ambulance
• D. Police car

ANS: A

64. Which of the following statements comparing a transverse wave and a longitudinal wave are correct?

(1) When a transverse wave travels through a medium, the particles in the medium do not move along with the wave. However, when a longitudinal wave travels through a medium, the particles in the medium move along with the wave.

(2) In a transverse wave, the vibrations of the transmitting medium are perpendicular to the direction of travel of the wave. In a longitudinal wave, the vibrations are along the direction of travel of the wave.

(3) The wave equation applies to both transverse waves and longitudinal waves.

• A. (1) and (2) only
• B. (1) and (3) only
• C. (2) and (3) only
• D. (1), (2) and (3)

ANS: C

65. A method of making a network system or a computer resistant to software errors, hardware problems or power failures

• A. Firewall
• B. Kerberos
• C. Fault-tolerant
• D. Sledge Hammer

ANS: C

66. The frequency spectrum near 2 GHz used for land based microwave and some mobile satellite communications

• A. X-band
• B. Ku-band
• C. S-band
• D. C-band

ANS: C

67. Satellite in high altitude orbit are typically park in a temporary orbit to between the initial low earth orbit and the final high-altitude orbit to minimize the energy required for transfer, and such orbit is known as

• A. Stephen transfer orbit
• B. Clarke transfer orbit
• C. Pierce transfer orbit
• D. Hohmann transfer orbit

ANS: D

68. Two equal amplitude tones have a power of +10 dBm, and generate a pair of equal amplitude 3rd-order intermodulation products at -20 dBm. What is the 2-tone, 3rd-order intercept point (IP3) of the system?

• A. +25 dBm
• B. +20 dBm
• C. +40 dBm
• D. +15 dBm

ANS: A

69. What is a primary advantage to using 90 degree (quadrature) hybrid couplers in amplifier designs?

• A. Low noise figure
• B. Input/output impedance not dependent on devices as long as device impedances are equal
• C. Wider bandwidth possible
• D. Higher S/N ratio

ANS: B

70. In a composite video signal what is the relationship between the amplitude of the signal and the intensity of the electron beam in the receiver picture tube?

• A. No effect
• B. The lower the amplitude the darker the picture
• C. The greater the amplitude the lighter the picture
• D. The greater the amplitude the darker the picture

ANS: D

71. What is the power dynamic range of an ideal 12-bit analog-to-digital converter (ADC)?

• A. 12.87 dB
• B. 36.12 dB
• C. 72.25 dB
• D. 120 dB

ANS: C

72. An ideal 10 dB attenuator is added in front of a load that has a 2.00:1 VSWR. What is the resulting VSWR of the load + attenuator?

• A. 12.0:1
• B. 2.10:1
• C. 1.07:1
• D. 5.4:1

ANS: C

73. What is the thermal noise power in a 1 MHz bandwidth when the system temperature is 15 degrees Celsius (assume gain and noise figure are 0 dB)?

• A. -114.0 dB
• B. -114.0 dBm/Hz
• C. -114.0 dBm
• D. -114.0 dBw

ANS: C

74. Find the energy in one photon at a wavelength of 1310 nm.

• A. 0.94 eV
• B. 1.52 eV
• C. 1.89 ev
• D. 5.13 eV

ANS: A

75. An uplink at 14 GHz requires a saturation flux density of -91.4 dBW/m² and an input backoff of 11 dB. The satellite Gt is -6.7dBK^-1, and receiver feeder losses amount to 0.6 dB. Calculate the C/N density ratio.

• A. 37.93 dB
• B. 55.69 dB
• C. 74.5 dB
• D. 83.66 dB

ANS: C

76. What is the carrier level for blanking?

• A. 67.5%
• B. 12.5% + 2.5%
• C. 100%
• D. 75% + 2.5%

ANS: D

77. The part of the wireless system's infrastructure that controls one or multiple cell sites' radio signals, thus reducing the load on the switch

• A. Home Location Register
• B. Visitor Location Register
• C. Base station controller
• D. Base Transceiver Station

ANS: C

78. Which feature of a “stealth” aircraft is most responsible for its low observability?

• A. Multi-faceted surfaces
• B. Radar absorbent paint
• C. Minimal use of metals in airframe
• D. Large RCS

ANS: B

79. What is the lowest modulation index at which an FM carrier is suppressed?

• A. π (3.1416)
• B. 2.40
• C. Only AM carriers can be suppressed
• D. 2π

ANS: B

80. A global system for mobile communications-based PCS network used outside of the U.S.

• A. GSM
• B. EDGE
• C. CNETZ
• D. DCS 1800

ANS: D

81. The splitting of a spectrum license into two or more licenses of fewer frequencies

• A. Band reduction
• B. Disaggregation
• C. Allocation
• D. Splitting

ANS: B

82. What circuit function is found in all types of receivers?

• A. BFO
• B. An RF amplifier
• C. A detector
• D. An audio filter

ANS: C

83. Which phone standard supports the highest data rate?

• A. GPRS
• B. iDEN
• C. GSM
• D. EDGE

ANS: D

84. _________is an analog modulation scheme in which the amplitude of a relatively high-frequency carrier signal is varied in accordance with the instantaneous amplitude of an information signal.

• A. Pulse Modulation
• B. QAM
• C. Angle Modulation
• D. Amplitude Modulation

ANS: D

85. Entry of a designated frequency channel in the agreed plan, adopted by the ITU, for use by one or more nations for a terrestrial or space radio communication services in one or more identified countries or geographic areas and under specified conditions.

• A. Allotment
• B. Emission
• C. Allocation
• D. Assignment

ANS: A

86. A TDR display shows a discontinuity 1.4 µs from the start. If the line has a velocity factor of 0.8 how far is the fault from the reflectometer?

• A. 16.8 m
• B. 168 m
• C. 325 m
• D. 32.5 m

ANS: B

87. Introduced by AT&T Network Systems in 1991. Enables service providers to define, test and introduce new multimedia messaging, PCS and cell routing

• A. Packet Network
• B. Virtual Private Network
• C. Advanced intelligent network
• D. Ethernet

ANS: C

88. The standard operating system of a wireless network; technologies include AMPS, TDMA, CDMA and GSM

• A. Node B
• B. Unix
• C. Topology
• D. Air interface

ANS: D

89. The Japanese standards-setting organization

• A. NTT (Nippon Telephone & Telegraph)
• B. ARIB (Association of Radio Industries and Businesses)
• C. Docomo
• D. JDC (Japanese Digital Cellular)

ANS: B

90. The ________ is deflected horizontally and vertically to fill the screen area.

• A. permanent magnet
• B. yoke
• C. electron beam
• D. raster

ANS: C

91. A mask for dot trios has about ____ holes.

• A. 3
• B. 30,000
• C. 3,000
• D. 300,000

ANS: D

92. Calculate the limit of visibility of an earth station at the equator, with the antenna pointing either west or east along the horizontal.

• A. 85.3°
• B. 88.3°
• C. 81.3°
• D. 84.3°

ANS: C

93. What is a radar cross-section (RCS)?

• A. Target height and elevation
• B. A target’s reflection coefficient relative to a perfectly reflecting spherical surface of 1 m² cross-section
• C. The plane through which a radar signal passes through a target
• D. An engineering isometric drawing showing a slice through the equipment rack(s)

ANS: B

94. ________ adjustments cause the three electron beams to excite the correct colors on the screen.

• A. Comb
• B. Color
• C. Convergence
• D. Gamma

ANS: C

95. Which of the following factors will affect the degree of diffraction when a train of water waves passes through a slit?

(1) The width of the slit

(2) The wavelength of the wave

(3) The amplitude of the wave

• A. (1) and (2) only
• B. (1) and (3) only
• C. (2) and (3) only
• D. (1), (2) and (3)

ANS: A

96. A fiber link is to be installed with the following characteristics:

Transmitter: laser diode with Pt = 1mW

Receiver: APD with minimum Pr = -57dBm

Tx/Rx port losses 6 dB each

Two connectors at 1 dB each

Five splices at 0.5 dB each

Fiber total loss 2 dB/km

Fiber total dispersion 0.505 ns/km

Maximum desired bit rate 35 Mbps

Determine the loss-limited line length for a loss margin of 5 dB

• A. 1.78 km
• B. 17.8 km
• C. 178 km
• D. 0.178 km

ANS: B

97. Authorization given by a nation for a radio station to use a radio-frequency channel under specified conditions.

• A. Allotment
• B. Emission
• C. Allocation
• D. Assignment

ANS: D

98. In FCC former designation, P2D means _________.

• A. Telegraphy; pulse-carrier tone-modulated
• B. Telephony; pulse-width modulated
• C. Telephony; amplitude-modulated pulses
• D. Telegraphy; pulse-width tone-modulated

ANS: A

99. Crosstalk are considered to be intelligible to the listener when?

• A. At least 2 words are intelligible in 7-s period
• B. At least 7 words are intelligible in 4-s period
• C. At least 2 words are intelligible in 2-s period
• D. At least 4 words are intelligible in 7-s period

ANS: D

100. A CDMA mobile measures the signal strength from the base as -100 dBm. What should the mobile transmitter power be set to?

• A. 250 mW
• B. 54 mW
• C. 320 mW
• D. 43 Mw

ANS: A

Complete List of Communications Engineering Exams: ECE Pre-Board

---

This is 100 items set of Practice Examination 14 in Communications Engineering (Electronics Systems and Technology) composed of previous Board Exams Questions. Read each questions and choices carefully! Choose the best answer. In the actual board, you have to answer 100 items in Communications Engineering within 5 hours. You have to get at least 70% to pass the subject. Communications Engineering is 30% of the total 100% Board Rating along with Mathematics (20%), General Engineering and Applied Sciences (20%) and Electronics Engineering (30%). Familiarize each and every questions to increase the chance of passing the ECE Board Examination.

Start the Test Yourself Exam 14

Choose the letter of the best answer in each questions.

1. An area within a wireless communications system where there is no coverage

• A. Dead spot
• B. Hotspot
• C. Weakspot
• D. G-spot

ANS: A

2. The world’s first active repeater satellite

• A. Sputnik 1
• B. Telstar 1
• C. Courier 1B
• D. Echo 1

ANS: C

3. Which FCC regulation governs the unlicensed ISM band?

• A. Subsection 11
• B. Chapter 11
• C. Part 15
• D. 815.00

ANS: C

4. The person behind the first network email

• A. Ray Tomlinson
• B. Bill Gates
• C. Steve Jobs
• D. Tim Berner Lee

ANS: A

5. What is the horizontal scanning time for 20 pixels?

• A. 1.5 µsecs
• B. 2.5 µsecs
• C. 2 µsecs
• D. 0.125 µsecs

ANS: B

6. Calculate the maximum distance between base and mobile that can be accommodated with a guard time of 123 µs.

• A. 25.3 km
• B. 36.9 km
• C 8.5 km
• D. 12.4 km

ANS: C

7. In a satellite system, Johannes Kepler stated that “the square of the periodic time of orbit is proportional to the cube of the mean distance between the primary and the satellite’. This is also known as _____.

• A. Kepler’s 3rd law
• B. Kepler’s 2nd law
• C. Kepler’s 1st law
• D. Kepler’s law of areas

ANS: A

8. A ghost is displaced 1 inch on a 13-inch diagonal TV screen. Determine the time between signal receptions, and the difference in path lengths.

• A. 3.53 km
• B. 1.53 km
• C. 2.53 km
• D. 0.53 km

ANS: B

9. Slang term for someone who breaks an encrypted computer code or circuitry

• A. Programmer
• B. Cracker
• C. Engineer
• D. Hacker

ANS: B

10. An FCC designation for any carrier or licensee whose wireless network is connected to the public switched telephone network and/or is operated for profit

• A. Gateway
• B. CMRS (Commercial Mobile Radio Service)
• C. PSTN (Public Switched Telephone Network)
• D VAN (Value Added Network)

ANS: B

11. Placement of multiple antennas at a common physical site to reduce environmental impact and real estate costs and speed zoning approvals and network deployment

• A. Frequency reuse
• B. Collocation
• C. Multiplexing
• D. Duplexing

ANS: B

12. Why is there a frequency term in the equation for free-space path loss?

• A. Atmospheric absorption
• B. Antenna geometry requires it
• C. Because of the distance involved
• D. There is no frequency term

ANS: B

13. What is a primary advantage of offset-quadrature-phase shift-keying (OQPSK) over standard QPSK?

• A. Greater spectral efficiency
• B. More constant envelope power
• C. Greater data rates possible
• D. Lower noise density

ANS: B

14. One of the standard units for radiation dosimetry, but is not applicable to alpha, beta, or other particle emission and does not accurately predict the tissue effects of gamma rays of extremely high energies.

• A. curie
• B. roentgen
• C. gray
• D. Sievert

ANS: B

15. A moving target 0 degrees from the nose.

• A. dead ahead
• B. on starboard bow
• C. dead astern
• D. on port quarter

ANS: A

16. The monitoring, manipulating and troubleshooting of computer equipment through a wireless network

• A. Wireless ethernet
• B. Wireless IT
• C. WiFi (Wireless Fidelity)
• D. Radio sounding

ANS: B

17. Consider a video signal that has a resolution of 640 x 480 pixels, with a frame rate 0f 30 Hz using progressive scanning. The luma signal is sampled using 8 bits/sample. The two chroma channels also use 8 bits/sample, but the color resolution is ¼ that is used for luma. Find the approximate bit rate for this signal, neglecting synchronization, error correction, and compression.

• A. 110.6 Mbps
• B. 1.6 Mbps
• C. 10.6 Mbps
• D. 11.6 Mbps

ANS: A

18. The principle of data reduction which says that when reducing a set of data into the form of an underlying mode, one should be maximally non-committal with respect to missing data.

• A. Jaynes maximum entropy principle
• B. Maximum Entropy Principle
• C. Kullback principle of minimum discrimination
• D. Minimum discrimination principle

ANS: A

19. A photodiode has a responsivity of 0.35 A/W; calculate the diode current if the input optical power is 400 nW.

• A. 400 nA
• B. 140 nA
• C. 35 nA
• D. 410 Na

ANS: B

20. Which two systems are most likely to experience concurrent operation problems?

• A. Bluetooth + WLAN
• B. GSM + W-CDMA
• C. Bluetooth + AMPS
• D. WLAN + GSM

ANS: A

21. Which best describes a bi-static radar?

• A. Uses static electricity for both transmitted and received signals
• B. Only detects fixed (non-moving) targets
• C. Fixed transmitter and fixed receiver at different locations
• D. Fixed transmitter and fixed receiver at the same locations

ANS: C

22. In a network with 25 computers, which topology would require the most extensive cabling?

• A. Bus
• B. Star
• C. Mesh
• D. Ring

ANS: C

23. Bluetooth is also known as

• A. IEEE 802.12.1
• B. IEEE 802.15x
• C. IEEE 802.11b
• D. IEEE 802.15.1

ANS: D

24. Calculate the combine traffic intensity in erlang for the following calls:

Trunk 1: 32min and 15 sec Trunk 2: 17min and 41 sec

Trunk 3: 6min and 22 sec Trunk 4: 15min and 3 sec

Trunk 5: 24min

• A. 5.78 Erlang
• B. 1.6 Erlang
• C. 24.12 Erlang
• D. 231.5 Erlang

ANS: B

25. Calculate the noise voltage for a 1-kΩ resistor at 17° C “tuned” by an LC circuit with a BW of 1 MHz.

• A. 50.1 µV
• B. 15.01 µV
• C. 535.01 µV
• D. 5.01 µV

ANS: D

26. In 1800, ______discovered infrared light using a prism and a thermometer.

• A. William Herschel
• B. Johann Wilhelm Ritter
• C. Thomas Young
• D. Louis Malus

ANS: A

27. The electric field of a GSM antenna at 90m distance

• A. 0.05 V/m
• B. 0.005 V/m
• C. 0.5 V/m
• D. 5 V/m

ANS: C

28. In satellite terminology, LTO means

• A. low transfer orbit
• B. lift transfer orbit
• C. light transfer orbit
• D. lunar transfer orbit

ANS: D

29. Parceling a spectrum license into two or more geographic areas

• A. Cell splitting
• B. Partitioning
• C. Zoning
• D. Spectruming

ANS: B

30. The latest form of battery technology, allowing the highest power-to-weight ratio and no "memory effect," which plagues batteries made from other materials

• A. Nickel Cadmium
• B. Lithium Ion
• C. Nickel Metal Hydride
• D. Lead Acid

ANS: B

31. An antenna system whose technology enables it to focus its beam on a desired signal to reduce interference

• A. Smart antenna
• B. Loop antenna
• C. Array system
• D. Parasitic arrays

ANS: A

32. Procedure in which two base stations-one in the cell site where the phone is located and the other in the cell site to which the conversation is being passed- both hold onto the call until the handoff is completed

• A. Break before make
• B. Hard handoff
• C. Roaming
• D. Soft handoff

ANS: D

33. The scientist who is credited with coining the word "television".

• A. John Logie Baird
• B. Allen DuMont
• C. Vladimir Zworykin
• D. Constantin Perskyi

ANS: D

34. Picture tubes have two black conductive coating made of ________.

• A. Tellurium
• B. Phospor
• C. Aquadag
• D. Arsenic

ANS: C

35. Suppose that the aspect ratio of a TV system were change from 4:3 to 2:1, with the horizontal resolution keeping the same ratio to vertical resolution as at present. Assume the number of scan lines remains at present. How many details would have to be shown on a horizontal line?

• A. 428
• B. 338
• C. 674
• D. 525

ANS: C

36. Calculate the apogee of a MEO satellite which has a minor axis of 10,000 mi and has an orbital eccentricity of 1/10.

• A. 2,357.6 mi
• B. 6,819.5 mi
• C. 5,527.7 mi
• D. 23,300 mi

ANS: C

37. The polarization of light was discovered in 1808 by the French physicist __________.

• A. William Herschel
• B. Johann Wilhelm Ritter
• C. Thomas Young
• D. Louis Malus

ANS: D

38. An inverse-square law indicating the magnitude and direction of electrostatic force that one stationary, electrically charged object of small dimensions exerts on another

• A. Newton’s law
• B. Coulomb's law
• C. Len’z law
• D. Gauss’s law

ANS: B

39. Courier 1B used approximately and

• A. 5,000 solar cells
• B. 19,000 solar cells
• C. 36,000 solar cells
• D. 22,300 solar cells

ANS: B

40. Under section 1 of the proposed NTC memorandum circular on the rules and regulation on the allocation and assignment of 3G radio frequency band, what is the radio frequency band allocated for Band C and D to be used by 3G networks

• A. Band C : 1920 – 1935 MHz/2110 – 2125 MHz, Band D : 1935 – 1950MHz/2125 – 2140MHz
• B. Band C : 1950 – 1965 MHz/2140 – 2155 MHz, Band D : 1885 – 1900 MHz/1965 – 1980 MHz
• C. Band C : 2010 – 2025 MHz, Band D : 1935 – 1950 MHz/2125 – 2140 MHz
• D. Band C : 1920 – 1935 MHz/2110 – 2125 MHz, Band D : 1950 – 1965 MHz/2140 – 2155 MHz

ANS: B

41. In 1923 and 1929, _____ invented Iconoscope television camera tube and Kinescope TV picture tube respectively.

• A. John Logie Baird
• B. Allen DuMont
• C. Vladimir Zworykin
• D. William Crookes

ANS: C

42. The loss in single-mode fiber-optic cable due to the glass is about:

• A. 40 dB per km
• B. 4 dB per km
• C. 0.4 dB per km
• D. zero loss

ANS: C

43. AM radio's main limitation is its susceptibility to

• A. ignition noise
• B. Rayleigh fading
• C. transit time noise
• D. atmospheric interference

ANS: D

44. A basic AM radio transmitter works by first _________ the modulating signal, then multiplying it with the _________ using a _________

• A. AC-shifting, modulation index, integrator
• B. DC-shifting, modulation index, frequency mixer
• C. AC-shifting, carrier wave, differentiator
• D. DC-shifting, carrier wave, frequency mixer

ANS: D

45. For an Ethernet bus that is 500 meters in length using a cable with a velocity factor of 0.66, and a communication rate of 10 Mb/s, calculate the total number of bits that would be sent by each station before it detects a collision, if both stations begin to transmit at the same time.

• A. 5 bits
• B. 2.5 bits
• C. 50 bits
• D. 25 bits

ANS: D

46. In a CATV system, CMTS stands for

• A. Cable Modem Terminal Server
• B. Cable Modem Transmission System
• C. Cable Modem Terminal System
• D. Cable Modem Transmission Server

ANS: A

47. Which specification standard incorporates the Ethernet standard?

• A. EIA's RS232C
• B. CCITT's X.25
• C. IBM's Token Ring
• D. IEEE's 802.3

ANS: D

48. Which of these is NOT a problem with using symmetric private key cryptography?

• A. brute force attack can be used to uncover key
• B. transporting key between users
• C. decrypting long messages takes too much time
• D. loss or theft of key nullifies security

ANS: C

49. The _____ of the picture tube is the total angle that the beam can be deflected without touching the sides of the envelope.

• A. deflection angle
• B. critical angle
• C. optical angle
• D. envelope angle

ANS: A

50. The method of measuring absorption coefficient of sound which considers all angles of increase is called _________

• A. reverberation chamber method
• B. bounce back to back method
• C. distance method
• D. sound velocity method

ANS: B

51. Which of the following is referred to as disadvantage of using a squelch circuit?

• A. Effect of AGC is reduced for strong signals
• B. Very weak signal might not be received
• C. Receiver sensitivity is reduced for strong signals
• D. Receiver selectively is reduced for strong signals

ANS: B

52. Picture tubes have two black conductive coating made of _________.

• A. Tellurium
• B. Phospor
• C. Aquadag
• D. Arsenic

ANS: C

53. A wireless phone that uses mobile satellite service to send voice and data

• A. PDA
• B. Satellite phone
• C. Mobile phone
• D. Smart phone

ANS: B

54. A unique number assigned to every wireless operator in the United States that is then programmed into the phones that subscriber's to that service purchase

• A. System Identification Number
• B. Numeric Assignment Module
• C. Subscriber Identity Module
• D. International Mobile Subscriber Identity

ANS: A

55. The world's first operational packet switching network, and the progenitor of the global Internet.

• A. DECNET
• B. ARPANET
• C. ISDN
• D. NMT

ANS: B

56. A signaling technique that broadcasts the same signal over each site in a network

• A. Telecast
• B. Simulcast
• C. Polling
• D. Contention

ANS: B

57. Federal government authorization for use of specific frequencies or frequency pairs within a given allocation, usually at stated a geographic location(s)

• A. Spectrum division
• B. Spectrum assignment
• C. Spectrum alignment
• D. Spectrum cap

ANS: B

58. Calculate the energy related to the frequency occupied by VLF.

• A. 124 µeV to 1.24 µeV
• B. 1.24 peV to 12.4 peV
• C. 12.4 peV to 124 peV
• D. 124 meV to 1.24 Ev

ANS: C

59. Electromagnetic waves of much lower frequency than visible light were predicted by ________ and subsequently discovered by ________.

• A. Maxwell, Hertz
• B. Marconi, Hertz
• C. Hertz, Maxwell
• D. Gauss, Gilbert

ANS: A

60. An international high speed signaling backbone for the public switched telephone network

• A. Subscriber loop signaling
• B. Channel Associated signaling
• C. Signaling System 7
• D. DTMF signaling

ANS: C

61. ________ governs the exchange of sequential data

• A. IBM SNA
• B. SDLC
• C. FTP
• D. TCP

ANS: D

62. The integration of wireless communications, vehicle monitoring systems and location devices

• A. Cellular
• B. Telematics
• C. Networking
• D. Telewireless

ANS: B

63. ______ routes outgoing and recognizes incoming messages

• A. IP
• B. TCP
• C. HDLC
• D. ATM

ANS: A

64. In 1983, _____ protocols replace Network Control Program as the principal protocol of the ARPANET

• A. HDLC
• B. TCP/IP
• C. BISYNC
• D. SPX/IPX

ANS: B

65. The first email was sent in

• A. 1951
• B. 1961
• C. 1971
• D. 1981

ANS: C

66. Europe's approach to standardization for third-generation cellular systems

• A. IMT-TC
• B. UMTS
• C. 3GPP
• D. CDMA2000

ANS: B

67. The first satellite to use Nickel Cadmium storage batteries.

• A. Courier 1B
• B. Explorer 1
• C. Score
• D. Early Bird

ANS: A

68. In 1801, ______ discovered ultraviolet light using silver chloride, and again a prism.

• A. William Herschel
• B. Johann Wilhelm Ritter
• C. Thomas Young
• D. Louis Malus

ANS: B

69. The angle from the ascending node to perigee, measured in the orbital plane at the earth’s center, in the direction of satellite motion.

• A. Argument of perigee
• B. Mean anomaly
• C. True anomaly
• D. Right ascension of the ascending node

ANS: A

70. A unipolar NRZ line code is converted to a multiple level signal for transmission over a channel. The number of possible values in the multilevel signal is 32, and the signal consists of rectangular pulses that have a pulse width of 0.3472 ms. What is the equivalent bit rate for the multilevel signal?

• A. 28.8 kbps
• B. 56 kbps
• C. 7.2 kbps
• D. 14.4 kbps

ANS: D

71. Ethernet uses a ________ physical address that is imprinted on the network interface card (NIC).

• A. 32-bit
• B. 6-byte
• C. 64-bit
• D. 32-byte

ANS: B

72. The range of an IRDA system is ________.

• A. 1 foot
• B. 10 feet
• C. 1 meter
• D. 10 meters

ANS: C

73. A third-generation wireless standard proposal based on TDMA technology that was developed by the Universal Wireless Communications Consortium and is one of the 3G candidates submitted to the International Telecommunication Union by the United States

• A. IMT-TC
• B. DECT
• C. EDGE
• D. UWC-136

ANS: D

74. A limit to the allocated spectrum designated for a specific service

• A. Guardband
• B. Spectrum tolerance
• C. Drift
• D. Spectrum cap

ANS: D

75. Satellite receive dishes for telemetry and other remote monitoring, usually smaller than VSATs

• A. picoSAT
• B. USAT
• C. nanoSAT
• D. XSAT

ANS: B

76. A protocol designed for advanced wireless devices allowing the easy transmission of data signals, particularly Internet content, to micro-browsers built into the device's software

• A. Bisync
• B. WAP
• C. TCP
• D. SMTP

ANS: B

77. What circuit combines signals from an IF amplifier stage and a beat-frequency oscillator (BFO), to produce an audio signal?

• A. A power supply circuit
• B. An AGC circuit
• C. A detector circuit
• D. A VFO circuit

ANS: C

78. The Institute of Electrical and Electronics Engineers standard for wireless local area network interoperability

• A. 802.10.x
• B. 802.11.x
• C. 802.12.x
• D. 802.13.x

ANS: B

79. What two factors determine the sensitivity of a receiver?

• A. Intermodulation distortion and dynamic range
• B. Cost and availability
• C. Dynamic range and third-order intercept
• D. Bandwidth and noise figure

ANS: D

80. What is the term for the average power supplied to an antenna transmission line during one RF cycle at the crest of the modulation envelope?

• A. Peak output power
• B. Peak envelope power
• C. Peak transmitter power
• D. Average frequency power

ANS: B

81. ______ amount of material which will produce 1 nuclear decay per second.

• A. 1 roentgen
• B. 1 becquerel
• C. 1 curie
• D. 1 rad

ANS: B

82. What circuit has a variable-frequency oscillator connected to a driver and a power amplifier?

• A. A single-sideband transmitter
• B. A VFO-controlled transmitter
• C. A crystal-controlled transmitter
• D. A packet-radio transmitter

ANS: B

83. A collector modulated class c amplifier has a carrier output power of 100 W, and with an efficiency of 60 %, calculate the transistor power dissipation, assuming that all the power dissipation that occurs comes from the transistor.

• A. 34 W
• B. 66 W
• C. 60 W
• D. 100 W

ANS: B

84. As per NTC M.C. 07-08-2004 an MPSC (Mobile Phone Service Center) shall properly identify its business and location by posting conspicuously at the entrance of its premises a signboard of at least ________ dimension which shall indicate clearly its business name, the type of services it offers, its full business address and the MPSC permit number.

• A. 50 cm x 150 cm
• B. 100 cm x 50 cm
• C. 50 cm x 100 cm
• D. 150 cm x 100 cm

ANS: C

85. A single mode fiber is made with a core diameter of 10 µm and is coupled to a light source with a wavelength of 1.3 µm. Its core glass has a refractive index of 1.55. Determine the maximum value of the fractional difference of index.

• A. Δ = 0.000206
• B. Δ = 0.00806
• C. Δ = 0.00206
• D. Δ = 0.00086

ANS: C

86. The most common screen phosphor is P1 for ______ screen.

• A. blue
• B. green
• C. red
• D. yellow

ANS: B

87. The drum of a facsimile machine is 70.4 mm, and the scanning is 0.2 mm per scan. Calculate the index of cooperation for CCITT and IEEE standard respectively.

• A. 245, 123
• B. 353, 1106
• C. 1106, 353
• D. 1432, 144

ANS: C

88. A specification from the Consultative Committee on International Telephone and Telegraph on layered protocols connecting computer terminals to a public, packet-switched network

• A. Frame Relay
• B. ISDN
• C. X.25
• D. IP (Internet Protocol)

ANS: C

89. The acute radiation exposure effect of 100-200 dose of rems is ________.

• A. Slight blood changes
• B. Significant reduction in blood platelets and white blood cells
• C. Severe blood damage, nausea, hair loss, hemorrhage, death in many cases
• D. Death in less than two months for over 80%

ANS: B

90. Voltage of typical X-ray tube

• A. 2 to 20 kV
• B. 10 to 20 kV
• C. 30 to 200 kV
• D. 3 to 20 KV

ANS: C

91. What circuit uses a limiter and a frequency discriminator to produce an audio signal?

• A. A superheterodyne receiver
• B. A double-conversion receiver
• C. An FM receiver
• D. A variable-frequency oscillator

ANS: C

92. A special fee that local phone companies are allowed to charge customers for the right to connect with the local phone network.

• A. Access fee
• B. Toll charge
• C. Access charge
• D. Airtime

ANS: A

93. A type of advanced smart antenna technology that continually monitors a received signal and dynamically adapts signal patterns to optimize wireless system performance

• A. Phased array antennas
• B. Helical antenna
• C. Adaptive array antennas
• D. Parabolic antenna

ANS: C

94. A mixer has the following input frequencies: RF = 800 MHz, LO = 870 MHz. The desired output frequency is 70 MHz. What is the image frequency?

• A. 500 MHz
• B. 940 MHz
• C. 140 MHz
• D. 1670 MHz

ANS: B

95. In wireless technology, _____ refers to transporting voice and data traffic from a cell site to the switch

• A. Backbone
• B. Backhaul
• C. Routing
• D. Switching

ANS: B

96. An enhanced system overlay for transmitting and receiving data over cellular networks

• A. X.75
• B. Packet switching
• C. Cellular Digital Packet Data
• D. Nordic Mobile Telephone

ANS: C

97. What is the spurious-free dynamic range of a system with IP3 = +30 dBm and a minimum discernible signal (MDS) level of -90 dBm?

• A. 60 dB
• B. 80 dB
• C. 120 dB
• D. 150 dB

ANS: B

98. A network technology for both local and wide area networks (LANs and WANs) that supports real time voice and video as well as data

• A. Ethernet
• B. CSMA/CD (Carrier Sense Multiple Access/ Collision Detection)
• C. Wireless Ethernet
• D. ATM (Asynchronous Transfer Mode)

ANS: D

99. A spectrum analyzer displays a component at 10 MHz @ 0 dBm, 30 MHz @ -10 dBm, 50 MHz @ -14 dBm, 70 MHz @ - 17 dBm, and all of the other odd harmonics until they disappear into the noise. What was the most likely input signal that caused the spectrum?

• A. A 10 MHz cosine wave (0 Vdc)
• B. A 10 MHz triangle wave (0 Vdc)
• C. A 10 MHz sawtooth wave (0 Vdc)
• D. A 10 MHz square wave (0 Vdc)

ANS: D

100. On which side of a rectangular waveguide is an E-bend made?

• A. short dimension
• B. inside
• C. outside
• D. long dimension

ANS: A

Complete List of Communications Engineering Exams: ECE Pre-Board

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This is 100 items set of Practice Examination 12 in Electronics Engineering composed of previous and/or poterntial Board Exams Questions. Read each questions and choices carefully! Choose the best answer. In the actual board, you have to answer 100 items in Electronics Engineering within 5 hours. You have to get at least 70% to pass the subject. Electronics Engineering is 30% of the total 100% Board Rating along with Mathematics (20%), General Engineering and Applied Sciences (20%) and Electronics Systems and Technology (30%).

Start the Test Yourself Exam 12

Choose the letter of the best answer in each questions.

1. An advantage of an electromagnet over a permanent magnet is that:

• A. An electromagnet can be switched on and off
• B. An electromagnet does not have specific polarity
• C. An electromagnet requires no power source
• D. Permanent magnets must always be cylindrical

ANS: A

2. The quantity of magnetism retained by a magnetic material after withdrawal of the magnetized force is called

• A. Leftover magnetism
• B. Residual magnetism
• C. Hysteresis
• D. Coercivity

ANS: B

3. Three resistors of 10, 15, and 20 Ω each are connected in parallel. What is the total conductance?

• A. 0.217 S
• B. 3.41 S
• C. 4.62 S
• D. 0.52 S

ANS: A

4. What temperature in which the specific resistance of materials is usually measured?

• A. 290 K
• B. 300 K
• C. 20°C
• D. 0°C

ANS: C

5. When one resistance in a series string is open, the

• A. current is maximum in the normal resistances
• B. current is zero in all of the resistances
• C. voltage is zero across the open resistance
• D. current increases in the voltage source

ANS: B

6. The equivalent wye element of 3 equal resistors each equal to R and connected in delta is

• A. R
• B. 3R/2
• C. R/3
• D. 3R

ANS: C

7. A lead storage battery is rated at 12 V. If the internal resistance is 0.01 Ω, what is the maximum power that can be delivered to the load?

• A. 1,200 W
• B. 7,200 W
• C. 3,600 W
• D. 1,800 W

ANS: C

8. A simple circuit having a source of 7 nanovolts and a load of 3 kilo-mega ohms has a current equivalent to

• A. 23.33 amperes
• B. 2.333 attoamperes
• C. 2.333 amperes
• D. 2.333 deca amperes

ANS: B

9. What happens to the flow of electrons in electronic circuit when the resistance is increased?

• A. The speed of flow will remain constant
• B. The flow become faster
• C. The flow will be decreased
• D. No flow will occur

ANS: C

10. A circuit contains an inductor of 10 H in series with the capacitor of 0.001 F and operating at a frequency of 4 MHz. What is the net reactance or X in MΩ?

• A. 2.4727
• B. 2472.7
• C. 247.27
• D. 24.727

ANS: D

11. What is the relationship between frequency and the value of R?

• A. R varies indirectly
• B. R varies indirectly
• C. Frequency has no effect
• D. R varies directly

ANS: C

12. Longest life cell capable of 20, 000 times charged-discharged cycle and could last 30 years or over

• A. Nickel-cadmium cell
• B. Lithium cell
• C. Nickel hydrogen
• D. Alkaline cell

ANS: C

13. It is considered to be a negative charge of electricity?

• A. Atom
• B. Electron
• C. Neutron
• D. Proton

ANS: B

14. Refers to a field surrounding electrons and protons at stationary period indicating a stored energy

• A. Magnetic field
• B. Electrostatic field
• C. Electron field
• D. Electrodynamic field

ANS: B

15. The time required to complete one complete cycle of a waveform

• A. Crest
• B. Wavelength
• C. Frequency
• D. Period

ANS: D

16. Lines of flux generated by one winding which do not link the other winding

• A. Flux loss
• B. Leakage flux
• C. Reactance leakage
• D. Inductance leakage

ANS: A

17. What determines whether a substance is an insulator or a conductor?

• A. Number of protons
• B. Number of Photons
• C. Number of valence electrons
• D. Number of neutrons

ANS: C

18. Which of the following is positive electricity?

• A. Resinous dynamic electricity
• B. Vitreous dynamic electricity
• C. Vitreous static electricity
• D. Resinous static electricity

ANS: C

19. If the magnitude of the potential difference is generated by a single conductor passing through a magnetic field, which of the following statements is FALSE?

• A. The potential difference depends on the speed with which the conductor cuts the magnetic field
• B. The potential difference depends on the length of the conductor that cuts the magnetic field
• C. The potential difference depends on the magnetic field density that is present
• D. The potential difference depends on the diameter of the conductor that cuts the magnetic field

ANS: D

20. A current of 10-A flows through a 1 mm diameter wire. What is the average number of electrons that pass through a cross section of the wire per second?

• A. 1.6 x 10¹⁸ e/s
• B. 6.2 x 10¹⁸ e/s
• C. 1.6 x 10¹⁹ e/s
• D. 6.3 x 10¹⁹ e/s

ANS: D

21. Which of the following statements is true for steady-state conditions in a circuit powered by a dry a cell?

• A. Voltage is dependent upon time
• B. Capacitors behave as short circuits
• C. Inductors behave as short circuits
• D. Resistors behave as open circuits

ANS: C

22. What is the internal resistance of a 9 V battery that delivers 100 A when its terminals are shorted?

• A. 0.09 Ω
• B. 11 Ω
• C. 1.0 Ω
• D. 90 Ω

ANS: A

23. The change in the direction of a compass needle, when a current-carrying wire is brought near, is:

• A. Electromagnetic deflection
• B. Electrostatic force
• C. Magnetic force
• D. Electroscopic force

ANS: A

24. Suppose a certain current in a galvanometer causes the needle to deflect 20 degrees, and then this current is doubled. The needle deflection:

• A. Will decrease
• B. Will stay the same
• C. Will increase
• D. Will reverse direction

ANS: C

25. A unidirectional form of DC can be derived from which of the following sources?

• A. Battery
• B. Generator
• C. Rectifier circuits
• D. Power supply

ANS: B

26. 2.4 V of DC voltage can be obtained from how many NiMH cells connected in series?

• A. 2
• B. 3
• C. 4
• D. 6

ANS: A

27. A dc voltage is applied across a certain value of resistance. If the resistance value is halved, by what factor must the voltage be multiplied if the dissipated power is unchanged?

• A. 0.5 W
• B. 0.25 W
• C. 4 W
• D. 0.707 W

ANS: D

28. You have an unlimited supply of 1-W, 1000-Ω resistors, and you need a 500-Ω resistance rated at 7 W or more. This can be done by assembling:

• A. Four sets of two 1000-Ω resistors in series, and connecting these four sets in parallel
• B. Four sets of two 1000-Ω resistors in parallel, and connecting these four sets in series
• C. A 3x3 series-parallel matrix of 1000-Ω resistors
• D. Something other than any of the above

ANS: A

29. Where are electrons being pumped in a circuit powered by a battery?

• A. From negative terminal around to positive terminal
• B. from positive terminal around to negative terminal
• C. back and forth from the terminal to terminal
• D. all of the choices

ANS: A

30. Bleeder resistors:

• A. Are connected across the capacitor in a power supply
• B. Keep a transistor from drawing too much current
• C. Prevent an amplifier from being overdriven
• D. Optimize the efficiency of an amplifier

ANS: A

31. Which of the following method/laws defines a node every junction in the network that represents a connection of three or more branches?

• A. Kirchhoff’s Current Law
• B. Kirchhoff’s Voltage Law
• C. Nodal method
• D. Maxwell’s method

ANS: C

32. A major feature of a pot-core winding is:

• A. High current capacity
• B. Large inductance in small volume
• C. Efficiency at very high frequencies
• D. Ease of inductance adjustment

ANS: B

33. As an inductor core material, air:

• A. Has excellent efficiency
• B. Has high permeability
• C. Allows large inductance in a small volume
• D. Has permeability that can vary over a wide range

ANS: A

34. How many nodes are needed to solve an electrical network using nodal method?

• A. All the nodes in the circuit
• B. All nodes less one node
• C. Five nodes
• D. All nodes less two nodes

ANS: B

35. The power loss in an iron-core transformer or other AC devices as a result of magnetic hysteresis

• A. Inductive loss
• B. Hysteresis loss
• C. Magnetic loss
• D. Magnetic power loss

ANS: B

36. What is the inferred absolute zero temperature of silver?

• A. -243°C
• B. -236°C
• C. -234.5°C
• D. -242°C

ANS: A

37. Which of the following materials increase very slightly in resistance with a rise in temperature?

• A. Conductor
• B. Insulator
• C. Dielectric
• D. Alloy

ANS: D

38. What static electricity can be produced by rubbing silk on a glass rod?

• A. Resinous electricity
• B. Vitreous electricity
• C. Positive static electricity
• D. Negative static electricity

ANS: B

39. Determine how long a battery will last whose rating is 100 Ah, 24 V and will run a 300-W electronic equipment and 50-W light.

• A. 26.65 hours
• B. 50.05 hours
• C. 6.85 hours
• D. 12.00 hours

ANS: C

40. The resistance of 575 m of a certain wire of 21.85Ω. How much must be cut off to reduce the resistance to 14.25 Ω?

• A. 375 m
• B. 575 m
• C. 20 m
• D. 200 m

ANS: D

41. If the fifth color in a carbon composition resistor coding is brown, what is the failure rate (%/1000-hr)?

• A. 1
• B. 0.001
• C. 0.1
• D. 0.01

ANS: A

42. Two 0.1 µF capacitors are connected in parallel across a 120-Vdc source. The voltage source is then removed and a third unchanged 0.1 µF capacitor is connected across the parallel combination. What is the voltage across the third capacitor?

• A. 80 V
• B. 60 V
• C. 120 V
• D. 40 V

ANS: A

43. A resistor of 0.0044 siemens, a capacitor whose susceptance is 0.035 Siemens, and a coil whose susceptance is -0.011 siemens are all connected in parallel. The admittance vector is:

• A. 0.0044 + j0.024
• B. 0.035 – j0.011
• C. -0.011 - j0.035
• D. 0.0044 + j0.046

ANS: A

44. Which of the following is negative electricity?

• A. Dynamic electricity
• B. Resinous static electricity
• C. Vitreous static electricity
• D. Vitreous electricity

ANS: B

45. Air works well as a dielectric mainly because it:

• A. Has a high dielectric constant
• B. Is not physically dense
• C. Has low loss
• D. Allows for large capacitance in a small volume

ANS: C

46. Which of the following types of capacitors is polarized?

• A. Paper
• B. Mica
• C. Interelectrode
• D. Electrolytic

ANS: D

47. A copper wire has a resistance of 5 Ω. What is the resistance of another copper wire at the same temperature with length twice as long but with one half the diameter?

• A. 25 Ω
• B. 15 Ω
• C. 40 Ω
• D. 20 Ω

ANS: C

48. To get the Thevenin voltage, you have to

• A. short the voltage source
• B. short the load resistor
• C. open the load resistor
• D. open the voltage source

ANS: C

49. If a capacitor has a negative temperature coefficient:

• A. Its value decreases as the temperature rises
• B. Its value increases as the temperature rises
• C. Its value does not change with temperature
• D. It must be connected with the correct polarity

ANS: A

50. A conductor of unknown length has a diameter of 250 mils and a resistance of 280 Ω. By several successive passes through drawing dies, the diameter is reduced to 50 mils. Assuming that the resistivity of the conductor remains unchanged in the drawing process, what is the resistance of the reduced size wire?

• A. 175 Ω
• B. 250 Ω
• C. 560 Ω
• D. 150 Ω

ANS: A

51. Mercuric oxide is a primary cell with a nominal open circuit voltage of

• A. 1.35 V
• B. 2.1 V
• C. 1.25 V
• D. 1.5 V

ANS: A

52. What resistor is commonly used in power circuits?

• A. Carbon composition resistor
• B. Thin-film resistor
• C. Wire-wound resistor
• D. Potentiometer

ANS: C

53. A coil of 3.50 µH and a capacitor of 47.0 pF are in parallel. The frequency is 9.55 MHz. There is nothing else in series or parallel with these components. What is the admittance vector?

• A. 0 + j0.00282
• B. 0 – j0.00194
• C. 0 + j0.00194
• D. 0 – j0.00758

ANS: B

54. Which of the following is not a characteristic of mica capacitors?

• A. High efficiency
• B. Small size
• C. Capability to handle high voltages
• D. Low loss

ANS: B

55. A vector pointing “southeast” in the GB plane would indicate the following:

• A. Pure conductance, zero susceptance
• B. Conductance and inductive susceptance
• C. Conductance and capacitive susceptance
• D. Pure susceptance, zero conductance

ANS: B

56. Which tolerance color is GMV?

• A. Red
• B. Silver
• C. Gold
• D. Yellow

ANS: D

57. What voltage can be applied across a capacitor for a very short period of time?

• A. Transient voltage
• B. working voltage
• C. Surge voltage
• D. Plate voltage

ANS: C

58. When an alternating voltage reverse in polarity, the current it produces

• A. reverse in direction
• B. has a steady DC value
• C. has a phase angle of 180°
• D. alternate at 1.4 times the frequency of the applied voltage

ANS: A

59. The inductance of a coil can be continuously varied by:

• A. Varying the frequency
• B. Varying the net core permeability
• C. Varying the current in the coil
• D. Varying the wavelength

ANS: B

60. A copper-wire conductor with 0.2 in diameter has an area of

• A. 200 cmil
• B. 20, 000 cmil
• C. 40, 000 cmil
• D. 400 cmil

ANS: C

61. The hot resistance of the tungsten in a bulb is higher than its cold resistance because the filament’s temperature coefficients is

• A. negative
• B. positive
• C. zero
• D. about 10 Ω per degree

ANS: B

62. Which of the following does not increase the loss in a transmission line?

• A. Reducing the power output of the source
• B. Increasing the degree of mismatch between the line and the load
• C. Reducing the diameter of the line conductors
• D. Raising the frequency

ANS: A

63. Power factor is defined as the ratio of:

• A. True power to VA power
• B. True power to imaginary power
• C. Imaginary power to VA power
• D. Imaginary power to true power

ANS: A

64. Which of the following is the temperature coefficient of resistance of silver?

• A. 0.00393
• B. 0.0039
• C. 0.00382
• D. 0.0038

ANS: D

65. In the sign convention of Kirchhoff’s laws, if we traverse in the direction of current in a resistance, it is

• A. voltage rise
• B. voltage drop
• C. positive
• D. negative

ANS: B

66. The shell method of transformer winding:

• A. Provides maximum coupling
• B. Minimizes capacitance between windings
• C. Withstands more voltage than other winding methods
• D. Has windings far apart but along a common axis

ANS: A

67. A type of resistor with typical resistance values range from 2.7 Ω to 22 MΩ

• A. Wire-wound resistor
• B. Carbon composition
• C. Thin-film resistor
• D. Potentiometer

ANS: B

68. What is the dielectric strength of air dielectric?

• A. 150 V/mil
• B. 75 V/mil
• C. 75 V/in
• D. 150 V/in

ANS: B

69. What is current in a chemical cell?

• A. It is a movement of positive hole charges
• B. It is a movement of positive and negative ions
• C. It is a movement of positive ions only
• D. It is a movement of negative ions only

ANS: B

70. To get the Norton current, you have to

• A. short the load resistor
• B. open the voltage source
• C. open the load resistor
• D. short the voltage source

ANS: A

71. Which of the following is the strongest dielectric material?

• A. Glass
• B. Paper
• C. Teflon
• D. Rubber

ANS: A

72. A 2 MΩ resistor and a 2 µF capacitor are connected in series across a 100-V source. How much time is required for the voltage across the capacitor to be 63 V?

• A. 1 s
• B. 2 s
• C. 3 s
• D. 4 s

ANS: D

73. Which of these core types, in general, is best if you need a winding inductance of 1.5 H?

• A. Air core
• B. Ferromagnetic solenoid core
• C. Ferromagnetic toroid core
• D. Ferromagnetic pot core

ANS: D

74. An advantage of a toroid core over a solenoid core is:

• A. The toroid works at higher frequencies
• B. The toroid confines the magnetic flux
• C. The toroid can work for dc as well as for ac
• D. It’s easier to wind the turns on a toroid

ANS: B

75. Which solution to network problems involves a set of independent loop currents assigned to as many as meshes as there are in a circuit?

• A. KCL
• B. KVL
• C. Nodal method
• D. Maxwell’s method

ANS: D

76. In the body-end-dot method of coding for composition/wire-wound/thin-film resistor, the dot represents

• A. First significant digit
• B. Second significant digit
• C. Multiplier
• D. tolerance

ANS: C

77. At five time constants, the transient current is how much percent of its steady state value?

• A. 98.2%
• B. 86.8%
• C. 99.3%
• D. 95%

ANS: C

78. A method of solution applicable only to linear and bilateral networks

• A. Kirchhoff’s laws
• B. Nodal method
• C. Maxwell’s method
• D. Superposition theorem

ANS: D

79. High voltage is used in long-distance power transmission because:

• A. It is easier to regulate than low voltage
• B. The I²R losses are lower
• C. The electromagnetic fields are stronger
• D. Smaller transformers can be used

ANS: B

80. In a household circuit, the 234-V power has:

• A. One phase
• B. Two phases
• C. Three phases
• D. Four phases

ANS: C

81. What is the unit of electric field strength or intensity?

• A. N/C
• B. N/m
• C. V/m
• D. Both A and C

ANS: D

82. The zero-degree phase point in an ac sine wave is usually considered to be the instant at which the amplitude is:

• A. Zero and negative-going
• B. At its negative peak
• C. Zero and positive-going
• D. At its positive peak

ANS: C

83. What is the susceptance (in Siemens) of a circuit if the impedance is 1 – j2 Ω?

• A. 2
• B. 0.1
• C. 0.2
• D. 0.4

ANS: D

84. A coil has a reactance of 4.00 Ω. What is the admittance vector, G + jB, assuming nothing else is in the circuit?

• A. 0 + j0.25
• B. 0 + j4.00
• C. 0 – j0.25
• D. 0 + j4.00

ANS: C

85. If an alternating voltage is given by V = 30 sin 314t, what is the time required by the voltage to reach its negative peak for the first time?

• A. 0.03 s
• B. 0.02 s
• C. 0.015 s
• D. 0.1 s

ANS: C

86. The impedance of an RC circuit is 100 Ω. If the circuit current leads the applied by the voltage by 45˚, then what is the capacitive reactance?

• A. 70.7 Ω
• B. 100 Ω
• C. 141.42 Ω
• D. 50 Ω

ANS: A

87. What will happen to the susceptance of a capacitor if the frequency is doubled, all other things being equal?

• A. It will decrease to half its former value
• B. It will not change
• C. It will double
• D. It will quadruple

ANS: C

88. A 200 V, 50 Hz inductive circuit takes a current of 10 A, lagging 30˚. The inductive reactance of the circuit is

• A. 20 Ω
• B. 10 Ω
• C. 17.32 Ω
• D. 16 Ω

ANS: B

89. What is the power factor of an AC circuit with 6 Ω resistance and 12 Ω inductive reactance?

• A. 0.8 lagging
• B. 0.5 lagging
• C. 0.8 leading
• D. 0.5 leading

ANS: B

90. A capacitor of 1 µF capacitance is charged to 100 V and then disconnected from the power supply. A second but uncharged capacitor of 3 µF is then connected across the first capacitor. The voltage across the parallel combination is

• A. 25 V
• B. 66 2/3 V
• C. 110 V
• D. 45 V

ANS: A

91. Two coils of inductance is 3 H, calculate the equivalent inductance of the combination if mutual inductance assists and if mutual inductance opposes the self-inductance respectively.

• A. 2.4 H and 1.4 H
• B. 6.25 H and 2.75 H
• C. 3.75 H and 0.94 H
• D. 16 H and 4H

ANS: C

92. How is electrical energy wasted in a circuit?

• A. Converted to vibration
• B. Dissipated as light
• C. Dissipated as heat
• D. Converted to radio waves

ANS: C

93. What is the rapidity with which the electrical current changes direction?

• A. period of alternating current
• B. Wavelength of alternating current
• C. frequency of alternating current
• D. ohms

ANS: C

94. What color bands will a resistor of 10 Ω ± 5% tolerance have

• A. Brown, Black, Black, Gold
• B. Brown, Black, Brown, Gold
• C. Brown, Brown, Black, Gold
• D. Brown, Brown, Brown, Gold

ANS: A

95. A current of 0.50 A flows in an electromagnet of negligible resistance when it is connected to a source of 120-V, 60 Hz alternating current. The inductance of the electromagnet is

• A. 0.01 mH
• B. 0.64 H
• C. 0.16 H
• D. 0.24 H

ANS: B

96. In a sine-wave AC circuit with X_L and R in series, the

• A. voltages across R and X_L are in phase
• B. voltages across R and X_L are 180° out of phase
• C. voltage across R lags the voltage across X_L by 90°
• D. voltage across R leads the voltage across X_L by 90°

ANS: C

97. Which of the theorems below is valid only in passive networks?

• A. Maximum power transfer theorem
• B. Compensation theorem
• C. Reciprocity theorem
• D. Millman’s theorem

ANS: C

98. Given a power supply with a no load voltage of 12 volts and full load voltage of 10 volts, what is the percentage of voltage regulation?

• A. 17%
• B. 80%
• C. 20%
• D. 83%

ANS: C

99. After two time constant, the capacitor in an RC circuit is changed to what percentage of the supply voltage?

• A. 36.8%
• B. 63.2%
• C. 36.55%
• D. 95%

ANS: C

100. The power factor of a certain circuit in which the voltage lags behind the current is 80%. To increase the power factor to 100%, it is necessary to add to the circuit additional

• A. resistance
• B. inductance
• C. capacitance
• D. impedance

ANS: B

Complete List of Electronics Engineering Exams: ECE Pre-Board

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