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 : Most internal noise comes from A. Shot noise B. Transit-time noise C. Thermal agitation D. Skin effect
Last Answer : C. Thermal agitation
Description : ________ is an electric noise produced by thermal agitation of electrons in conductor and semiconductor. A. External noise B. Internal noise C. Thermal noise D. Flicker
Last Answer : C. Thermal noise
Description : Considered as the main source of an internal noise. A. Device imperfection B. Thermal agitation C. Temperature change D. Flicker
Last Answer : B. Thermal agitation
Description : Noise caused by the thermal agitation of electrons in resistance. A. All of these B. Thermal noise C. Johnson’s noise D. White noise
Last Answer : A. All of these
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 : Noise occurring in the presence of signal resulting from a mismatch between the exact value of an analog signal and the closet available quantizing step in a digital coder. A. Quantizing noise B. Thermal noise C. Impulse noise D. Crosstalk
Last Answer : A. Quantizing noise
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 : Comparing the signal strength arriving at the driven element from the desired direction to the signal strength reaching the driver from the opposite direction. A. Directivity B. Sensitivity C. Beamwidth D. Front-to-back ratio
Last Answer : D. Front-to-back ratio
Description : Which circuit contributes most of the noise in a receiver? A. IF amplifier B. Demodulator C. AF amplifier D. Mixer
Last Answer : D. Mixer
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 : The front-end of a television receiver, having a bandwidth of 7Mhz, and operating at a temperature of 27˚C , consists of an amplifier having a gain of 15 followed by a mixer whose gain is 20. The ... equivalent noise resistance for this television receiver. A. 8760 Ω B. 875Ω C. 8.76Ω D. 0.876Ω
Last Answer : B. 875Ω
Description : The noise output of a resistor is amplified by a noiseless amplifier having a gain of 60 and a bandwidth of 20 kHz. A meter connected at the output of the amplifier reads 1mV RMS. If the bandwidth of the amplifier is reduced to ... does the meter read now? A. 0.5 mV B. 0.5 µV C. 5.0 mV D. 5.0 µV
Last Answer : A. 0.5 mV
Description : The first stage of a two-stage amplifier has a voltage gain of 10, a 600 Ω input resistor, a 1600Ω equivalent noise resistance and 27kΩ output resistor. For the second stage, these values are 25, 81kΩ, 19kΩ, and 1MΩ, ... this two stage amplifier. A. 2,518 kΩ B. 2,518 Ω C. 251.8 Ω D. 12,518 Ω
Last Answer : B. 2,518 Ω
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 : Referred to as the stage in the radio receiver that contributes most of the noise. A. IF amplifier B. Supply stage C. Speaker D. Mixer
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 : 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 : What is the reference level for noise measurement, F1A weighted? A. -90 dBm B. -82 dBm C. -67 dBm D. -85 dBm
Last Answer : D. -85 dBm
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 : The most common unit of noise measurement in white noise voltage testing. A. NPR B. dBm C. dBW D. dBrn
Last Answer : A. NPR
Description : The most common unit of noise measurement in white noise testing. A. dBw B. dBk C. dBm D. NPR
Last Answer : D. NPR
Description : What is the reference frequency of CCITT psophometric noise measurement? A. 800 Hz B. 1500 Hz C. 3400 Hz D. 1000 Hz
Description : Which of the following parts of the radio receiver represent the component that extracts the desire RF signal from the electromagnetic wave? A. AF amplifier B. Antenna C. Detector D. Crystal
Last Answer : B. Antenna
Description : Referred to an oscillator signal “leak through” from a properly neutralized amplifier such as a master oscillator power amplifier. A. Carrier B. Stray signal C. Back wave D. Loss wave
Last Answer : C. Back wave
Description : Circuit used to amplify the optical signal in fiber optics communications links. A. Attenuator B. Optical repeater C. Optical amplifier D. Generator
Last Answer : B. Optical repeater
Description : If the percentage modulation of an AM amplifier is 88% and the modulating signal is 1 volt, the carrier has an amplitude of _______________. A. 1.14 volts B. 0.88 volt C. 1.88 volts D. 0.12 volt
Last Answer : A. 1.14 volts
Description : What is meant by antenna gain? A. The final amplifier gain minus the transmission line losses (including any phasing lines present) B. The ratio of the amount of power produced by the antenna ... D. The numeric ratio relating the radiated signal strength of an antenna to that of another antenna
Last Answer : D. The numeric ratio relating the radiated signal strength of an antenna to that of another antenna
Description : The unit of measurement of noise is – (1) Decibel (2) Hertz (3) Amplifier (4) Acoustics
Last Answer : (1) Decibel Explanation: The decibel (dB) is the unit used to measure the intensity of sound or noise level. It is given in terms of a logarithmic function of a ratio of power intensities. One ... one bel, named in honor of Alexander Graham Bell who was the inventor of the telephone and phonograph.
Description : The unit of measurement of noise is (1) Decibel (2) Hertz (3) Amplifier (4) Acoustics
Last Answer : Decibel
Description : Under hill cost pricing, price is determined - (1) by adding a margin to the average cost (2) by comparing marginal cost and marginal revem (3) by adding normal profit to the marginal cost (4) by the total al cost of production
Last Answer : (1) by adding a margin to the average cost Explanation: Full cost pricing is a practice where the price of a product is calculated by a firm on the basis of its direct costs per unit of output ... is known as 'full-cost' pricing. The price is equal to 'full' cost, including an acceptable profit.
Description : Under full cost pricing, price is determined (1) by adding a margin to the average cost (2) by comparing marginal cost and marginal revenue (3) by adding normal profit to the marginal cost (4) by the total cost of production
Last Answer : by adding a margin to the average cost
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
Description : External noise originating outside the solar system A. Cosmic noise B. Solar noise C. Thermal noise D. Lunar noise
Last Answer : A. Cosmic noise
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 : 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. 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 : 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 : 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 : Two resistors, 20kΩ, and 50kΩ are at ambient temperature. Calculate for a bandwidth equal to 100kHz, the thermal noise voltage for the two resistors connected in parallel. A. 0.4782µV B. 4278 µV C. 4.78 µV D. 47.8 µV
Last Answer : C. 4.78 µV
Description : Background noise is the same as the C. Thermal noise D. Gaussian noise 24. ECE Board Ex
Last Answer : A. Impulse noise
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 : 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 : Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF (150MHz) marine-band receiver? A. Man-made noise B. In the atmosphere C. In the receiver front end D. In the ionosphere
Last Answer : C. In the receiver front end
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 : Three identical circuits having 10 dB signal noise-to-noise ratio each are connected in tandem with each other, what is the overall S/N? A. 5.23 dB B. 14.77dB C. 30 dB D. 40 dB
Last Answer : A. 5.23 dB
Description : Unwanted radio signal on assigned frequency. A. Splatter B. RFI C. Noise D. EMI
Last Answer : C. Noise
Description : Which causes a quantization noise in PCM system? A. Serial transmission errors B. The approximation of the quantized signal C. The synchronization between encoder and decoder D. Binary coding techniques
Last Answer : B. The approximation of the quantized signal
Last Answer : The approximation of the quantized signal