Electrical Engineering · Question Bank

Communications

408 of 408 questions match · page 17 of 21. Answer in your head first, then check the solution.

TypeAll 408Problem solvingObjective 408
✕ Clear filters
#321📘 reviewer_appEasy
A circuit that compares the frequency of the noncrystal carrier oscillator to a crystal reference oscillator and then produces a correction voltage proportional to the difference between the two frequencies
AAFC
BSquelch circuit
CAGC
DHeterodyning circuit
#322📘 reviewer_appEasy
In FM receivers, which of the ff rejects the image frequency?
Apreselector
Bdetector
CIF amplifier
Dmixer
#323📘 reviewer_appEasy
In FM receivers, which of the ff provides most gain and selectivity of the receiver?
Adetector
BRF amplifier
Clocal oscillator
DIF amplifier
#324📘 reviewer_appEasy
The final IF amplifier in FM receivers is sometimes called ___________
Atuned amplifier
Blimiter
Cpassband filter
Dany of these
#325📘 reviewer_appEasy
It is simply two-single ended slope detectors connected in parallel and fed 180 degrees out of phase
AFoster-Seeley discriminator
BQuadrature detector
CBalanced slope generator
DPLL detector
#326📘 reviewer_appEasy
Which of the ff tuned-circuit frequency discriminator is relatively immune to amplitude variations in its input signal?
Aratio detector
Bslope detector
Cbalanced slope detector
Dquadrature detector
#327📘 reviewer_appEasy
In FM demodulators, it is also called coincidence detector
AQuadrature demodulator
BPLL demodulator
CFoster-Seeley discriminator
DRatio detector
#328📘 reviewer_appEasy
In FM receivers, limiters produce a constant-amplitude output of all signals above a prescribed minimum input level called ___________
Atreshold level
Bcapture level
Cquieting level
Dany of these
#329📘 reviewer_appEasy
A crystal oscillator whose frequency can be changed by an input voltage is called _______
AVCO
BVXO
CVFO
DVHF
#330📘 reviewer_appEasy
Which of the ff frequency demodulators requires an input limiter?
AFoster-Seeley discriminator
BPulse-averaging discriminator
CQuadrature detector
DPLL
#331📘 reviewer_appEasy
Provides a slight automatic control over the local oscillator circuit and compensates for its drift that would otherwise cause a station to become detuned
AAGC
BAFC
CVVC
DVCO
#332📘 reviewer_appEasy
_______ of an FM receiver is the minimum dB difference signal strength between two received signals necessary for the capture effect to suppress the weaker signal
Acapture effect
Bcapture gain
Ccapture ratio
Dcapture loss
#333📘 reviewer_appEasy
When two limiter stages are used, this is called _______
Adouble limiting
Btwo-time limiting
Creserve limiting
Dratio limiting
#334📘 reviewer_appEasy
One of the prominent advantage of FM over PM is
AFM requires frequency multipliers to increase the modulation index and frequency deviation to useful levels
BThe voltage controlled oscillators of FM can be directly modulated and produce outputs with high frequency deviations and high modulation
CThe modulation index of FM is independent of the modulating signal frequency
DFM offers better signal-to-noise performance than FM
#335📘 reviewer_appEasy
Each speaker assembly at the receiver reproduces exactly the same information
Amonophonic
Bmultiphonic
Cstereophonic
Dany of these
#336📘 reviewer_appEasy
In a pulse averaging discriminator, the pulses are produced by an
AAstable multivibrator
BZero-crossing detector
COne shot
DLow-pass filter
#337📘 reviewer_appEasy
A VCO that is available as single IC chip called 566 is manufactured by:
AFairchild Semiconductor
BSignetics
CNational Semiconductor
DTexas Instruments
#338📘 reviewer_appEasy
The output amplitude of the phase detector in a quadrature detector is proportional to
Apulse width
Bpulse frequency
Cinput amplitude
Dthe phase shift value at center
#339📘 reviewer_appMedium
With stereo transmission, the maximum frequency deviation is
A75 kHz
B15 kHz
C25 kHz
D3 kHz
#340📘 reviewer_appEasy
The L + R channel occupies ________
A50 Hz to 15 kHz
B60 kHz to 74 kHz
C23 kHz to 53 kHz
D20 Hz to 20 kHz

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