Description : An advantage of optic fiber rejecting an induced noise signals from magnetic field or solar storms flux. A. Electric hazard B. Cross talk C. Immunity to noise D. Shielding
Last Answer : C. Immunity to noise
Description : What is the primary advantage of DSBSC in AM? A. Reduce bandwidth over standard AM B. All of these C. It is simpler to transmit and receive than the standard AM D. No transmitter power is wasted in the carrier
Last Answer : D. No transmitter power is wasted in the carrier
Description : Quantizing noise occurs in A. PCM B. PLM C. PDM D. PAM
Last Answer : A. PCM
Description : Binary communications systems are better because A. they can interface directly with the analog telephone network B. the components are simpler, less costly, and more reliable C. people think better in binary D. interstate calls are less costly
Last Answer : B. the components are simpler, less costly, and more reliable
Description : Choosing a discrete value that is near but not exactly at the analog signal level leads to a) PCM error b) Quantization error c) PAM error d) Sampling error
Last Answer : b) Quantization error
Description : The signals which are obtained by encoding each quantized signal into a digital word is called as a) PAM signal b) PCM signal c) FM signal d) Sampling and quantization
Last Answer : b) PCM signal
Description : The series of periodically recurrent pulses is modulated in amplitude by the corresponding instantaneous samples. A. PFM B. PWM C. PDM D. PAM
Last Answer : D. PAM
Description : 12 voice channels are sampled at 8000 sampling rate and encoded into 8 bit PCM word. Determine the rate of the data stream. a. 354 kbps b. 750 kbps c. 768 kbps d. 640 kbps
Last Answer : c. 768 kbps
Description : Highest theoretical frequency that can be processed at a sampling rate without aliasing. A. Folding frequency B. Resonant frequency C. Natural frequency D. Critical frequency
Last Answer : A. Folding frequency
Description : ECE Board Exam March 1996 According to the Nyquist theorem, the sampling rate that can be used in a PCM system is ________ the highest audio frequency. A. once B. eight times C. twice D. thrice
Last Answer : C. twice
Description : A major and basic advantage for the use of a klystron. A. High power B. Efficiency C. Lesser noise D. Cheaper
Last Answer : A. High power
Description : CMOS circuits are extensively used for ON-chip computers mainly because of their extremely (A) low power dissipation. (B) high noise immunity. (C) large packing density. (D) low cost.
Last Answer : Ans: C Because CMOS circuits have large packing density.
Description : What signal-to-noise ratio is required for satisfactory television reception? A. 10 dB B. 30 dB C. 40 dB D. 20 dB
Last Answer : C. 40 dB
Description : The signal to noise ratio that is required for a satisfactory television reception. A. 30 dB B. 40 dB C. 10 dB D. 20 dB
Last Answer : B. 40 dB
Description : What signal-to-noise ratio is required for satisfactory telephone services? A. 50 dB B. 30 dB C. 40dB D. 20 dB
Last Answer : A. 50 dB
Description : Which of the following is not a major benefit of fiber-optic cable? a. Immunity from interference b. No electrical safety problems c. Excellent data security d. Lower cost
Last Answer : b. No electrical safety problems
Description : Steps to follow to produce PCM signal. A. Quantizing, sampling, and coding B. Sampling, quantizing, and coding C. Sampling, coding and quantizing D. Coding, quantizing and coding
Last Answer : B. Sampling, quantizing, and coding
Description : Which of the following is an advantage to using fiber optics data transmission? a. resistance to data theft b. fast data transmission rate c. low noise level d. all of above
Last Answer : fast data transmission rate
Description : Which of the following low noise transistors is commonly used at microwave frequencies? A. MOSFET B. GASFET C. MESFET D. JFET
Last Answer : C. MESFET
Description : Deemphasis in the receiver in effect attenuates modulating signal components and noise in what frequency range? A. dc B. low C. intermediate D. high
Last Answer : D. high
Description : What causes image interference? A. Low gain B. High IF C. Poor front-end selectivity D. Low signal-to-noise ratio
Last Answer : C. Poor front-end selectivity
Description : What do you call the single booster installed on the antenna dish of satellite receiver? A. Low noise amplifier B. Single amplifier C. Noise amplifier D. Rectifier
Last Answer : A. Low noise amplifier
Description : Which of the following is not a way of minimizing if not eliminating noise? A. Use redundancy B. Increase transmitted power C. Reduce signaling rate D. Increase channel bandwidth
Last Answer : D. Increase channel bandwidth
Description : A coherent binary phase shift keyed BPSK transmitter operates at a bit rate of 20 Mbps with a carrier to noise ratio C/N of 8.8dB. Find Eb/No. A. 73 dB B. 62.4 dB C. 81.8 dB D. 8.8 dB
Last Answer : D. 8.8 dB
Description : Photodiodes used as fiber optic directors are a. Unbiased to generate a voltage same as a solar cell b. Forward bias c. Reversed bias d. Thermoelectrically cooled
Last Answer : c. Reversed bias
Description : What is Noise immunity ?
Last Answer : The maximum amount of noise in the input of a logic gate, which can provide a good output , is called Noise immunity .
Description : Which of the following is a disadvantage for plastic fiber optics? ∙ a. Noise immunity ∙ b. Electric hazards ∙ c. Higher losses ∙ d. All of these
Last Answer : c. Higher losses
Description : Down sampling is to make a digital image file smaller by A. removing pixels B. adding noise C. adding pixels D. removing noise
Last Answer : A. removing pixels
Description : The square of the thermal noise voltage generated by a resistor is proportional to A. its resistance B. its temperature C. the bandwidth over which it is measured D. All of the above
Last Answer : D. All of the above
Description : Indicate the false statement. Noise figure is defined as A. the ratio of the S/N power supplied at the input terminal of a receiver or amplifier to the S/N power supplied to the output or ... under test, both working at the same temperature over the same bandwidth and fed from the same source
Last Answer : C. an unwanted form of energy tending to interfere with the proper and easy reception and reproduction of wanted signals
Description : An amplifier operating over the frequency range of 455 to 460 kHz has a 200 kΩ input resistor. What is the RMS noise voltage at the input to this amplifier if the ambient temperature is 17˚C ? A. 40 µV B. 4.0 µV C. 400 µV
Last Answer : B. 4.0 µV
Description : Indicate the false statement A. The noise generated in a resistance or the resistive component of any impedance is random. B. Random noise power is proportional to the bandwidth over which is measured ... exist D. All formula referring to random noise are applicable only to the value of such noise.
Last Answer : C. A random voltage across the resistor does not exist
Description : The noise figure of the first circuit in tandem connection is 10.5 dB while its power gain is 15, what is the over all noise figure if the second circuit has a noise figure of 11 dB? A. 11.59 dB B. 11.23 dB C. 10.79 dB D. 10.5 dB
Last Answer : C. 10.79 dB
Description : At 17˚ C, the noise voltage generated by 5kΩ resistor, operating over a bandwidth of 20KHz is A. 1.3 nV B. 1.3 µV C. 1.3 pV D. 1.3 mV
Last Answer : B. 1.3 µV
Description : Man-made noise is usually from _______. A. transmission over power lines and by ground wave B. sky-wave C. space-wave D. troposphere
Last Answer : A. transmission over power lines and by ground wave
Description : Noise from random acoustic or electric noise that has equal energy per cycle over a specified total frequency band. A. Gaussian noise B. Whiter noise C. Thermal noise D. All of the above
Description : What noise is a transient short-duration disturbance distributed essentially uniformly over the useful passband of a transmission system? A. Flicker noise B. Transit-time noise C. Shot noise D. Impulse noise
Last Answer : D. Impulse noise
Description : What is the effect in over modulated amplitude modulated radio broadcasting transmission? A. Interference to adjacent channel B. Higher fidelity C. Increase noise D. Higher audio signal
Last Answer : A. Interference to adjacent channel
Description : Noise from random acoustic or electric noise that has equal per cycle over a specified total frequency band. A. Thermal noise B. White noise C. Gaussian noise D. All of these
Last Answer : D. All of these
Description : What is the advantage of widlar current source over constant current source?
Last Answer : Using constant current source output current of small magnitude(microamp range) is not attainable due to the limitations in chip area. Widlar current source is useful for obtaining small output currents.Sensitivity of widlar current source is less compared to constant current source.
Description : A device or instrument able to generate noise with accurate voltage for test purposes
Last Answer : noise generator
Description : The Boston Consulting Group classifies products that have a dominant market share but low prospects for growth and that generate more cash than is required to maintain market share as A)dogs. B)cash cows. C)stars. D)cash contributors. E)problem children.
Last Answer : B)cash cows.
Description : Do languages get simpler over time?
Last Answer : Languages change over time, but generally linguists and sociolinguists prefer not to characterize languages in terms of whether they are simple or complex. After a couple of hundred years of comparative ... they creolize (in the next generation) they become as complex as any other extant tongue.
Description : Stacking antenna elements A. increases sensitivity to weak signals B. will suppress odd harmonics C. decrease signal to noise ratio D. increases selectivity
Last Answer : A. increases sensitivity to weak signals
Description : Strong interference from one particular station can be eliminated by the use of A. noise limiters B. squelch circuits C. negative feedback D. wave traps in the antenna circuitry
Last Answer : D. wave traps in the antenna circuitry
Description : The major cause of atmospheric or static noise are A. Thunderstorms B. Airplanes C. Meteor showers D. All of these
Last Answer : A. Thunderstorms
Description : What do you call the noise coming from the sun and stars? A. Black-body noise B. Space noise C. Galactic noise D. All of these
Last Answer : B. Space noise
Description : What is the primary cause of atmospheric noise? A. Thunderstorm B. Lightning C. Thunderstorm and lightning D. Weather condition
Last Answer : B. Lightning
Description : The total noise power present in a 1-Hz bandwidth . A. Noise density B. Noise figure C. Noise limit D. Noise intensity
Last Answer : A. Noise density
Description : A noise whose source is within the solar system. A. Solar noise B. Thermal noise C. Cosmic noise D. Johnson Noise
Last Answer : A. Solar noise