This is the Section 3 Module 4 of the compiled Communications Coaching Materials taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies (EST), Communications Books, Journals and other Communications References. This particular Coaching Notes in Communications Engineering has random Questions and Answers in random topics. Make sure to familiarize each questions to increase the chance of passing the ECE Board Exam.
Communications Engineering Coaching: Section 3 Module 4
· Modem
Ans: PSK
· Absorption of impedance Tube
Ans: α = 4A1A2 / (A1+A2)2
· Impedance acoustics
Ans: Newton seconds per cubic meter
· WiMax data rate
Ans: 500 kbps – 8 Mbps
· Formula
Ans: ft = fo + kfoΔT
· Blind velocity
Ans: Vb = PRF(nλ/2)
· Spacing of transmission line
Ans: S = λL/360
· Transfer of one adjacent walls to another
Ans: Flanking transmission
· Range that accepts signal interference
Ans: Blocking range
· Sound deduction index
Ans: Transmission loss
· Internet cable 6 MHz
Ans: 27 Mbps
· Not terrestrial TV
Ans: 8-V.58
· Lowest attenuation UHF
Ans: N-type
· HF
Ans: affected by the solar cycle
· Pag tinanong linear bit PCM code
Ans: n-1
· Photon
Ans: E = hf/c h=6.634 x 10-34
· SSB
Ans: HF
· High Z
Ans: Crystal
· U600 bandwidth
Ans: 2520 MHz
· Standard VB
Ans: 300 – 3400 Hz
· Voice grade
Ans: 0 – 4 kHz
· 170 Ω/km Customer loop
Ans: AWG22
· Determine attenuation to troposcatter
Ans: Scatter angle
· Compression
Ans: SSB = 20 log cot(φ/2)
· Klystron
Ans: n +3/4
· Time
Ans: TD = 1.016 √ξr (length) ns/ft
0 = 360 TD / T
· One tenth of the wavelength
Ans: Elementary doublet
· FOC data rate
Ans: data rate = 1/5Dd
· Minimum height
Ans: λ/4
· Theoretical height
Ans: λ/2 vertical antenna
· LORAN C/D accuracy
Ans: 460 m
· COR/DME ground navigation
Ans: 108 – 118 MHz
· Repeater fiber optic cable
Ans: 10 – 30 km
· dBa
Ans: 1 uV/m
· Bridge
Ans: Physical and data link
· Transmission and reception of information
Ans: Session
· Transmission of bits
Ans: Physical
· Start bit
Ans: 0
· Stop bit
Ans: 1
· Noise temperature
Ans: 17°C
· AC cable
Ans: All of the above
· Not specification of 3G
Ans: IMT2000
· BW efficiency
Ans: Information density
· Resolution
Ans: Resolution = Vmax / DR
· Quantization error
Ans: Q = (1/2)Res
· Isolation CATV
Ans: 28 dB
· Output terminal match CATV
Ans: 16 dB
· Disadvantage of plastic over glass
Ans: High attenuation
· Mnimum illumination for reading
Ans: 8000 Ix
· Impedance at open end of half wave antenna
Ans: 2500 ohms
· Max data rate of fiber optic system
Ans: 10 Gbps
· Data rate of TDMA
Ans: 8 kbps
· WiMax
Ans: 500 kbps to 8 Mbps
· H21 broadband ISDN
Ans: 32.786 Mbps
· Data rate of terrestrial digital TV
Ans: 32.28 Mbps
· V.34
Ans: 33.6 kbps
· GPRS
Ans: 172.2 kbps
· Bluetooth
Ans: 72 kbps
· V.22
Ans: 1200 kbps
· V.90
Ans: 56 kbps
· V.32
Ans: 9.6 kbps
· Speed of IS-95 CDMA
Ans: 1.23 Mbps
· WiFi / wireless internet service provider
Ans: 11 Mbps
· WiFi spec
Ans: IEEE 802.11b
· Spacing between M88 loading coils
Ans: 9000 ft
· Area above the vertical antenna
Ans: curve of silence
· under the influence of the induction field
Ans: near field
· FM luminance frequency for VCR recording
Ans: 3.5 MHz
· Measure of comparison of sound intensity with another
Ans: decibel
· Used in optical system and satellite telemetry links
Ans: biphase codes
· Divide into 4 by ITU
Ans: Facsimile groups
· Code transparency with frequency
Ans: bit oriented protocol
· ERP of class 2 cellular mobile
Ans: 1.6 W
· Max power for class I analog mobile
Ans: 600 mV
· Appears at night
Ans: F2 layer
· High frequency daytime propagation
Ans: E layer
· MF range wavelength
Ans: Hectometric waves
· Protocol for packet switching networks
Ans: X.75
· Electronic serial number
Ans: 32 bits
· Most luminance
Ans: Yellow
· Used by Marconi antenna
Ans: below 2 MHz
· Mogul-Dellinger fadeout
Ans: sudden ionospheric disturbance frequency
· Most commonly used characters are represented in fewer bits
Ans: Huffman encoding
· On time of FETs
Ans: Acquisition time
· Term for byte in ATM
Ans: Octet
· Used in 10/100 Mbps Ethernet
Ans: ISTP cable
· Not used in TV
Ans: 108 MHz – 114 MHz
· Does not use error checking
Ans: Physical layer
· Demodulates audio signal in TV
Ans: Discriminator
· Together with mixer
Ans: local oscillator
· Not used in mobile tel.
Ans: balanced detector
· Guardband of C-band satellite comm.
Ans: 4 MHz
· Minimum quality circuit available in PTN
Ans: basic voice grade
· Multichannel network
Ans: broadband
· Standard test tone
Ans: 1000 Hz
· Average human absorption
Ans: 4.7 units or sabines
· Max. critical angle
Ans: Acceptance angle
· Software used in preparing packets
Ans: internet protocol
· No modulation
Ans: Rest frequency
· CMTS(AMPS)
Ans: Less than 2%
· Speed of longitudinal waves
Ans: is proportional to the compressibility of the medium
· EIRP Class II Cellular
Ans: 1.6 watts
· Pulse dialing
Ans: 10 pulses/sec or 600 pulses/minutes
· Single-sideband full-carrier
Ans: H3E
· Retain local number to access (migration)
Ans: Local number portability
· ‘raceway’
Ans: Header
· Fastest multimedia peripherals
Ans: Firewire
· Output Class I mobile output minimum
Ans: 600 mV
· Smallest unit data for network
Ans: Packet
· UTC
Ans: UTA
· Mod used for IS-95
Ans: QPSK (DSSS)
· Propagation delay for TDM period
Ans: 577 us
· Difference freq for forward and backward transmission
Ans: 45 MHz
· Gain at the direction of the major lobe
Ans: Directivity Gain
· Code transparency
Ans: Bit-oriented protocol
· AM broadcast antenna height
Ans: λ/2 vertical antenna
· Synchronization 1 V
Ans: Scanning line
· Can be eliminated using helical antenna
Ans: Faraday rotation
· Companding
Ans: protect small signals from quantizing distortion
· Current Maximum for ¼ wavelength Marconi Antenna
Ans: at the base
· Synchronous data transfer
Ans: CMT
· Electrical signals converted for microphone
Ans: 25 – 8000 Hz
· Reference sound level
Ans: 0 dBm
· Bessel 1.0 modulation index
Ans: 3 pairs of sidebands
· Common coaxial characteristic impedance
Ans: 50Ω and 75Ω
· Dead space
Ans: due to shading of hills and trees
Post a Comment