Description : Which of the following types of HPA is not used in earth stations? A. TWT B. Transistor C. Klystron D. Magnetron
Last Answer : D. Magnetron
Description : What is the advantage of sidetone? A. High transmission efficiency B. Results to a strengthened signal C. No energy dissipation D. Assures that the telephone is working
Last Answer : D. Assures that the telephone is working
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 advantage of PTM over PAM? A. All of these B. Low sampling rate is required C. Much better noise immunity D. Simpler to generate
Last Answer : C. Much better noise immunity
Description : The advantage of using top loading in a shortened HF vertical antenna is A. lower quality factor B. greater structural strength C. higher losses D. improved radiation efficiency
Last Answer : D. improved radiation efficiency
Description : What can be added to the basic two-cavity klystron to increase the amount of velocity modulation and the power output?
Last Answer : Intermediate cavities between the input and output cavities.
Description : ECE Board Exam March 1996 The expander in a companding device provides ___________. A. greater amplification for low signal levels B. less amplification for low signal levels C. greater amplification for high signal levels D. lesser pressure for transmission
Last Answer : B. less amplification for low signal levels
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 is the major cause of atmospheric or static noise? A. Sunspots B. Airplanes C. Meteor showers D. Thunderstorm
Last Answer : D. Thunderstorm
Description : What is the basic principle of operation of a klystron?
Last Answer : Velocity modulation
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 : 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 : ___________ is device that measures the internal open circuit voltage of an equivalent noise generator having an impedance of 600Ω and delivering noise power to a 600 Ω load. A. Psophometer B. Barometer C. Reflectometer D. Voltmeter
Last Answer : A. Psophometer
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 : The value of the resistor creating thermal noise is doubled. The noise power generated is therefore. A. halved B. quadrupled C. doubled D. unchanged
Last Answer : D. unchanged
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 : What is the unit of noise power of psophometer? A. pWp B. dBa C. dBm D. dBrn
Last Answer : A. pWp
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 : 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 : What limits the sensitivity of a receiver? A. The power supply of the receiver B. The power output of a transmitter C. The noise floor of the receiver D. The distance between the transmitter and receiver
Last Answer : C. The noise floor of the receiver
Description : What bandwidth is needed to support a capacity of 128 kbps when the signal power to noise power ratio in decibels is 100? A. 19224 Hz B. 3853 Hz C. 19244 Hz D. 3583 Hz
Last Answer : B. 3853 Hz
Description : A figure of merit used to measure the performance of a radiation detector. A. Noise equivalent power B. Ripple factor C. Safe factor D. Quality factor
Last Answer : A. Noise equivalent power
Description : Unit of noise power of psophometer A. dBa B. pWp C. dBm D. dBmO
Last Answer : B. pWp
Description : What does the noise weighting curve shows? A. Noise signals measured with a 144 handset B. Power levels of noise found in carrier systems C. The interfering effect of other frequencies in a voice ... a reference frequency of one kilohertz D. Interfering effects of signals compared with a 3-kHz tone
Last Answer : C. The interfering effect of other frequencies in a voice channel compared with a reference frequency of one kilohertz
Description : A cylinder roller creates lesser noise than a deep groove ball bearing. (a) True (b) False
Last Answer : (b) False
Description : Cylinder roller creates lesser noise than deep groove ball bearing. a) True b) False
Last Answer : b) False
Description : One of the following is a high powered RF ac basic transmitter that has two or more stages, the oscillator stage which determines the frequency opereation and RF amplifier stage orstages that develop the ... to develop a good frequency stability. A. Goldsmith B. MOPA C. Alexanderson D. Hartley
Last Answer : B. MOPA
Description : Noise consisting of irregular pulses of short duration and relatively high amplitude, A. Quantizing noise B. Tone interference C. Impulse noise D. Cross talk
Last Answer : C. Impulse noise
Last Answer : A. Quantizing noise
Description : Noise at the input to the receiver can be as high as several A. microvolts B. milivolts C. volts D. kilo volts
Last Answer : A. microvolts
Description : Which of the following is not a source of industrial noise? A. Automobile ignition B. Sun C. Electric Motors D. Leakage from high voltage line
Last Answer : B. Sun
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 is the non-continuous noise of irregular pulses or spikes of duration with high amplitudes? A. Wander B. Jitter C. Hits D. Singing
Last Answer : B. Jitter
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 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 : An antenna efficiency is computed by using one of the following equations. A. Efficiency = (radiation resistance / transmission resistance) B. Efficiency = (total resistance / radiation resistance) x ... / transmitter output) x 100% D. Efficiency = (radiation resistance / total resistance) x 100%
Last Answer : D. Efficiency = (radiation resistance / total resistance) x 100%
Description : _____ of an antenna is a measure of how the antenna concentrates its radiated power in a given direction. A. Efficiency B. Power C. Gain D. Polarization
Last Answer : C. Gain
Description : What is the term for the ration of the radiation resistance of an antenna to the total resistance of the system? A. Effective radiated power B. Beamwidth C. Radiation conversion loss D. Antenna efficiency
Last Answer : D. Antenna efficiency
Description : What is meant by the term antenna efficiency? A. Efficiency = effective radiated power/transmitter output x 100% B. Efficiency = radiation resistance/ transmission resistance C. Efficiency = total resistance/radiation resistance x 100% D. Efficiency = radiation resistance/total resistance x 100%
Last Answer : D. Efficiency = radiation resistance/total resistance x 100%
Description : An increase in the effective power radiated by an antenna in a certain desired direction at the expense of power radiated in other directions. A. Antenna gain B. Antenna back lobe ration C. Antenna total ration D. Antenna efficiency
Last Answer : A. Antenna gain
Description : Higher the number of stars, ________ will be the efficiency or EER a) Lesser c) Greater b) Likewise e) average
Last Answer : Greater
Description : Choose the correct statement about BEE Star rating label a. Higher the number of stars, greater will be the efficiency b. Lesser the number of stars, greater will be the efficiency c. Higher the number of stars, lesser will be the efficiency d. None of the above
Last Answer : Higher the number of stars, greater will be the efficiency
Description : Higher the number stars, EER or efficiency will be. A. Greater C. Lesser B. Moderate D. None of the above
Description : A major advantage of waste heat recovery in industry is a) Reduction in pollution c) Increase efficiency d) None of the above
Last Answer : Reduction in pollution
Description : Major advantage of waste heat recovery in industry is: a) Reduction in pollution b) increase in efficiency c) Both a & b d) none of the above
Last Answer : Both a & b
Description : Luminance efficiency is minimum for a a. Fluorescent tube b. High wattage light bulb c. Mercury vapor lamp d. Low wattage light bulb
Last Answer : d. Low wattage light bulb
Description : Luminous efficiency is least for a A. mercury vapor lamp B. low-wattage light bulb C. high-wattage light bulb D. fluorescent tube
Last Answer : B. low-wattage light bulb
Description : What type of klystron is used as the final stage of a power- amplifier transmitter?
Last Answer : Multicavity klystron.
Description : Debunching of the electron bunches in the higher modes of a reflex klystron has what effect on output power?
Last Answer : Power is reduced.