Multiple Choice Questions Topic Outline
- MCQs in Cells and Batteries
- MCQs in Electric Generator
- MCQs in Electronic Power Supply
- MCQs in Voltage Regulation
- MCQs in Photovoltaic/Thermoelectric Generator
- MCQs in Distribution Transformer
- MCQs in Uninterrupted Power Supply (UPS)
- MCQs in Float-Battery System
- MCQs in Converters
- MCQs in Inverters
The Series
Following is the list of multiple choice questions in this brand new series:
Start Practice Exam Test Questions Part 1 of the Series
1. A ______ is a group of cells that generates electric energy from their internal chemical reaction
- A. battery
- B. regulator
- C. power supply
- D. solar energy
2. Which of the following is the main function of a battery?
- A. To provide a source of steady DC voltage to fixed polarity
- B. To provide a source of steady dc voltage of variable polarity
- C. To provide a source of variable dc voltage of fixed polarity
- D. To provide a source of variable dc voltage of variable polarity
3. Volt is a unit of ______.
- A. electromotive force
- B. energy
- C. force
- D. magneto motive force
4. A transformer will work on
- A. ac only
- B. ac as well as dc
- C. dc only
- D. pulsating dc
5. In a chemical cell current is the movement of
- A. positive and negative ions
- B. positive charges
- C. positive ions only
- D. negative ions only
6. What is the nominal output of an automotive battery having six lead acid cells in series?
- A. 12 V
- B. 24 V
- C. 6 V
- D. 3 V
7. The speed of a dc motor is
- A. directly proportional to flux per pole
- B. inversely proportional to flux per pole
- C. inversely proportional to applied voltage
- D. inversely proportional to armature current
8. Low speed alternators are driven by
- A. hydraulic turbines
- B. steam turbines
- C. steam engines
- D. diesel engines
9. High speed alternators are driven by
- A. diesel engine
- B. steam turbines
- C. hydraulic turbines
- D. diesel engine
10. The common 9v flat battery for transistor radio has ____ cells connected in series
- A. 12
- B. 3
- C. 6
- D. 9
11. For the same rating, the size of low speed alternator is ______ that of high speed alternator
- A. about the same as
- B. less than
- C. more than
- D. twice
12. Which of the following is not a secondary cell?
- A. Silver-zinc
- B. Nickel-iron
- C. Silver-oxide
- D. Lead-acid
13. Which of the following is not a primary cell?
- A. Carbon-zinc
- B. Zinc-chloride
- C. Edison call
- D. Mercuric oxide
14. The brush voltage drop in a dc machine is about
- A. 0.1V
- B. 2V
- C. 10V
- D. 20V
15. Carbon brushes are used in a dc machine because
- A. carbon lubricates and polishes the commutator
- B. contact resistance is decreased
- C. carbon is cheap
- D. carbon is abundant
16. Considered as the main types of battery
- A. Lithium cell and alkaline
- B. Carbon-zinc dry cell and lead sulphuric wet cell
- C. Leclanche cell and carbon zinc
- D. Voltaic cell and lithium cell
17. Which of the following is the main function of a dc motor?
- A. to generate power
- B. to change mechanical energy to electrical energy
- C. to change electrical energy to mechanical energy
- D. to change chemical energy to mechanical energy
18. Which motor has the best speed regulation?
- A. Series
- B. Shunt
- C. Commutatively compounded
- D. Differentially compounded
19. A method of converting chemical energy into electric energy by dissolving two different conducting materials in an electrolyte
- A. Battery
- B. Cell
- C. Voltaic cell
- D. Charging
20. A commutatively compounded motor does not run at dangerous speed at light loads because of the presence of
- A. shunt winding
- B. interpoles
- C. series
- D. compensating windings
21. DC shunt motors are used in those applications where ______ is required
- A. high starting torque
- B. high no load speed
- C. practically constant speed
- D. variable speed
22. Galvanic cell is the other name of
- A. voltaic cell
- B. primary cell
- C. secondary cell
- D. solar cell
23. For the same rating _____ motor has the highest staring torque
- A. shunt
- B. differentially compounded
- C. commutatively compound
- D. series
24. The voltage regulation of an alternator with a power factor of 0.8 lagging is _____ at unity power factor
- A. greater than
- B. the same as
- C. smaller than
- D. 100%
25. Which is the most suitable for punch presses?
- A. shunt motor
- B. differentially compounded motor
- C. series motor
- D. commutatively compounded motor
26. In a vacuum cleaner, ______ motor is generally used
- A. shunt
- B. series
- C. commutatively compounded
- D. differentially compounded
27. A type of secondary cell that can be recharged but with an electrolyte that cannot be refilled
- A. Sealed rechargeable cell
- B. Sealed secondary cell
- C. Leclanche cell
- D. Alkaline cell
28. Silver cadmium is secondary cell with a nominal open circuit voltage of
- A. 1.1V
- B. 1.2V
- C. 1.5V
- D. 1.35V
29. Which is a variable speed motor?
- A. series
- B. commutatively compounded
- C. shunt
- D. differentially compounded
30. The most commonly used method of speed control of a dc motor is by varying
- A. voltage applied to the motor
- B. field strength
- C. effective number of conductors in series
- D. armature circuit resistance
31. What gives the relative activity in forming ion charges for some of the chemical elements?
- A. Electrochemical series
- B. Electrical series
- C. Electromotive series
- D. Both A and C above
32. The ac armature winding of an alternator is
- A. always star connected
- B. star delta connected
- C. generally delta connected
- D. pi connected
33. The air gap in an alternator is _____ in an induction machine
- A. much shorter than
- B. about the same as
- C. much longer than
- D. one-half than
34. Nickel-iron cells is a secondary cell with a nominal open- circuit voltage output of 1.2 and is otherwise known as
- A. Leclanche cell
- B. Galvanic cell
- C. Voltaic cell
- D. Edison cell
35. A dc series motor is most suitable for
- A. cranes
- B. lathes
- C. pump
- D. punch presses
36. Which of the most suitable motor fro elevator
- A. Series
- B. Differentially compounded
- C. Shunt
- D. Commutatively compounded
37. The voltage output of a cell depends on
- A. its elements
- B. electromotive series
- C. its electrodes
- D. electrochemical series
38. The alternators driven by _____ do not have a tendency to hunt
- A. diesel engines
- B. steam engines
- C. water turbines
- D. prime movers
39. Damper windings are used in alternators to
- A. prevent hunting
- B. achieve synchronism
- C. reduce wind age losses
- D. reduce eddy current loss
40. Leclanche cell is the other name of
- A. lead acid cell
- B. zinc chloride
- C. carbon zinc cell
- D. mercuric cell
41. the primary leakage flux links
- A. primary winding only
- B. secondary winding only
- C. both primary and secondary windings
- D. neither primary nor secondary windings
42. Overheating of a dc motor is often due to
- A. insufficient end play
- B. overloads
- C. loose parts
- D. rough commutator
43. A small 9V battery might be used to provide power to
- A. an electric stove
- B. an electronic calculator
- C. a personal computer
- D. a radio transmitter
44. The frequency of the system with which several alternators are parallel can be increased by simultaneously ________ of all generators
- A. increasing the field excitation
- B. decreasing the field excitation
- C. increasing the speed of prime movers
- D. decreasing the speed of prime movers
45. A transformer is an efficient device because it
- A. is a static device
- B. uses capacitive coupling
- C. uses inductive coupling
- D. uses electric coupling
46. The amount of back emf of shunt motor will increase when
- A. the load is increased
- B. the field is strengthen
- C. the field is weakened
- D. the load is decreased
47. Three cells connected in series from a
- A. battery
- B. voltage divider
- C. voltage multiplier
- D. hybrid
48. What can be found in a transformer with open-circuit test?
- A. Copper losses
- B. Turns ratio
- C. Total equivalent resistance
- D. Total equivalent leakage resistance
49. Transformers having ratings less than 5kva are generally
- A. oil cooled
- B. water cooled
- C. natural air cooled
- D. self cooled
50. An example of rechargeable dc source is an/a
- A. lithium battery
- B. photovoltaic cell
- C. optoisolator
- D. lead acid battery
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