Description : nif stands for A. Non-intrinsic figure B. Noise improvement factor C. Narrow intermediate frequency D. Noise interference figure
Last Answer : B. Noise improvement factor
Description : An FM receiver whose intermediate frequency is 10.7 MHz, is experiencing image channel interference from a station transmitting on 121.1 MHz. If the local oscillator is tracking above, the receiver is tuned to A. 131.8 MHz B. 110.4 MHz C. 142.5 MHz D. 99.7 MHz
Last Answer : D. 99.7 MHz
Description : Emission on a frequency or frequencies immediately outside the necessary bandwidth which result from the modulation process except spurious emission. A. Radiation B. Noise C. Out of the band D. Interference
Last Answer : C. Out of the band
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 : In cellular system, _____ defines the geographic distance that is required between cells using identical frequencies in order to avoid interference between the radio transmissions at these cells. A. frequency-reuse ratio B. distance-to-reuse ratio (D/R) C. reuse format plan ratio D. reuse factor
Last Answer : B. distance-to-reuse ratio (D/R)
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 : 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 : 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 : Noise that occurs via capacitive or inductive coupling in a cable. A. Crosstalk B. Quantizing noise C. Reference noise D. Tone interference
Last Answer : A. Crosstalk
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 : Form of interference caused by rain or dust storms. A. Precipitation static B. Shot-noise C. Galactic noise D. Impulse noise
Last Answer : A. Precipitation static
Description : _________ is the random and unpredictable electric signals from natural causes, both internal and external to the system. A. Interference B. Attenuation C. Distortion D. Noise
Last Answer : D. Noise
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 : The band of frequencies least susceptible to atmospheric noise and interference is: A. 30 – 300 kHz B. 300 – 3000 kHz C. 3 – 30 MHz D. 300 – 3000 MHz
Last Answer : D. 300 – 3000 MHz
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 : The random and unpredictable electric signal from natural causes, both internal and external to the system is know as ________. A. Distortion B. Noise C. Attenuation D. Interference
Last Answer : B. Noise
Description : A superhet receiver has an IF of 455 kHz and is experiencing image-channel interference on a frequency of 1570 kHz. The receiver is tuned to A. 1115 kHz B. 660 kHz C. 2025 kHz D. 910 kHz
Last Answer : B. 660 kHz
Description : What is the most commonly used intermediate frequency of radar receivers? A. 40 MHz B. 60 MHz C. 70 MHz D. 30 MHz
Last Answer : D. 30 MHz
Description : When measuring a transmitter’s frequency against a suitable standard, the frequency to be measured is taken from the A. oscillator stage B. intermediate amplifier C. buffer stage D. final RF stage
Last Answer : D. final RF stage
Description : ECE Board Exam March 1996 What is the purpose of a beat frequency oscillator (BFO)? A. Aid in the reception of weak voice-modulated signals B. Generates a signal, whose frequency is the ... reception D. Generates an output, whose frequency differs from that of the intermediate frequency by 1 kHz
Last Answer : C. Generates a 1kHz note for Morse code reception
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 : The transistor with the lowest noise figure in the microwave region is a A. MOSFET B. Dual-gate MOSFET C. JFET D. MESFET
Last Answer : D. MESFET
Description : Which noise figure represents the lowest noise in receiver? A. 1.6 dB B. 2.1 dB C. 2.7 dB D. 3.4 dB
Last Answer : A. 1.6 dB
Description : A receiver connected to an antenna whose resistance is 50 Ω has an equivalent noise resistance of 30Ω. Calculate its equivalent noise temperature if the noise figure is equal to 1.6. A. 17.4 K B. 174K C. 1.74K D. 17K
Last Answer : B. 174K
Description : Calculate the noise figure of the receiver whose RF amplifier has an input resistance of 1000Ω and an equivalent shot-noise resistance of 2000Ω, a gain of 25 and load resistance of 125 kΩ. Given that the bandwidth is 1. ... to an antenna with an impedance of 75Ω. A. 30.3 B. 3.03 C. 303 D. .303
Last Answer : A. 30.3
Description : Calculated the noise figure of the amplifier whose Req equals 2518Ω (RT=600Ω) if its driven by a generator whose output impedance is 50Ω. A. 39.4 B. 3.94 C. 394 D. 0.394
Last Answer : A. 39.4
Description : One of the following is not a useful quantity for comparing the noise performance receivers. A. Input noise voltage B. Equivalent noise resistance C. Noise temperature D. Noise figure.
Last Answer : A. Input noise voltage
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 : ECE Board Exam March 1996 The equivalent noise temperature of the amplifier is 25 K. What is the noise figure? A. 1.86 B. 0.1086 C. 1.086 D. 10.86
Last Answer : C. 1.086
Description : Crosstalk due to incomplete suppression of sidebands or to intermodulation of two or more frequency-multiplexed channels which is unintelligible is classified as A. Impulse noise B. Thermal noise C. Quantizing noise D. Miscellaneous noise
Last Answer : D. Miscellaneous noise
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. HF mixer are generally noisier than HF amplifiers. B. Impulse noise voltage is dependent on bandwidth C. Thermal noise is independent of the frequency at which is measured. D. Industrial noise is usually of the impulse type.
Last Answer : B. Impulse noise voltage is dependent on bandwidth
Description : Industrial noise frequency is between _____. A. 0 to 10 KHz B. 160 MHz to 200 MHz C. 15 to 160 MHz D. 200 to 3000 MHz
Last Answer : C. 15 to 160 MHz
Description : What is the reference frequency of CCIT phosphomeric noise measurement? A. 800 Hz B. 1000 Hz C. 1500 Hz D. 3400 Hz
Last Answer : A. 800 Hz
Description : Unwanted radio signal on assigned frequency. A. Splatter B. RFI C. Noise D. EMI
Last Answer : C. Noise
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
Last Answer : D. All of the above
Description : What is meant by the term modulation index? A. The processor index. B. The ratio between the deviation of a frequency modulated signal and the modulating frequency. C. The FM signal-to-noise ratio. D. The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency.
Last Answer : B. The ratio between the deviation of a frequency modulated signal and the modulating frequency.
Description : One of the following is not among the advantages of series modulation A. No transformer B. Suppressed white noise C. Simple D. Modulates any frequency
Last Answer : B. Suppressed white noise
Description : What is the reference frequency of CCITT psophometric noise measurement? A. 800 Hz B. 1500 Hz C. 3400 Hz D. 1000 Hz
Description : Industrial noise frequency is between _________. A. 200 to 3000 Mhz B. 15 to 160 Mhz C. 0 to 10 Khz D. 20 Ghz
Last Answer : B. 15 to 160 Mhz
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 : One of the reasons why FDM is being replaced by TDM is A. noise is amplified with voice when an FDM system is used B. it is difficult to place channels side by side C. there is more time than frequency D. Most available frequencies has been used
Last Answer : A. noise is amplified with voice when an FDM system is used
Description : The ratio of the level of the modulated output of a transmitter under conditions of standard test modulation to the level of the demodulated output with no modulation applied both measured with the ... . Reference audio output B. None of these C. Audio frequency response D. Residual noise level
Last Answer : D. Residual noise level
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 : What is the reliable measurement for comparing amplifier noise characteristics? A. Thermal agitation noise B. Noise factor C. Noise margin D. Signal-to-noise
Last Answer : B. Noise factor
Description : What is the noise factor if the equivalent noise temperature is 25 K? A. 1.09 B. 0.09 C. 0.36 dBm D. 0.36
Last Answer : A. 1.09
Description : The difference between the original and reconstructed signal gives rise to A. S factor B. Quantizing noise C. S/N D. Fade margin
Last Answer : B. Quantizing noise
Description : Differentiate between intrinsic and extrinsic semiconductor
Last Answer : Pure form of semiconductors are said to be intrinsic semiconductor. Ex: germanium, silicon. It has poor conductivity If certain amount of impurity atom is added to intrinsic semiconductor the resulting semiconductor is Extrinsic or impure Semiconductor It has good conductivity.
Description : It is the made from semiconductor material such as aluminum-galium-arsenide or gallium-arsenide-phosphide. A. APD B. Injection laser diode C. Light emitting diode D. Positive-intrinsic-negative
Last Answer : C. Light emitting diode