communication engineering Objective test for BEL BSNL and other PSU Exams

communication engineering Objective test for BEL BSNL and other PSU Exams
MCQ in Basic Communication theory for Jobs in
BSNL
MTNL
HAL
DRDO
BARC
SAIL
AAI
BEL
BHEL
BEML
DVC
GAIL
and other PSU Exams for Engineers







1. An example of communication service
a) printer
b) television
c) both(a)&(b)
d) none of these


Ans:b

2. Channel is
a) medium
b) signal
c) carrier
d) none of these

Ans:a

3. Analog signal varies with
a) sampling time
b) time continuously
c) sampling frequency
d) none of these

Ans:b

4. Carrier signal has
a) constant magnitude
b) constant frequency
c) variable frequency
d) variable time

Ans:a


5.Modulating signal has
a) low frequency
b) low modulation
c) high frequency
d) none of these

Ans:a

6. fc +fm is
a) upper band frequency
b) lower band frequency
c) mid band frequency
d) none of these

Ans:a


7. fc –fm is
a) upper band frequency
b) lower band frequency
c) mid band frequency
d) none of these

Ans:b



8. In amplitude modulation, amplitude is
a) constant
b) zero
c) variable
d) none of these

Ans:c


9. frequency modulation has
a) one carrier
b) one carrier with two side band frequencies
c) one carrier with infinite frequencies
d) none of these

Ans:c


10. Amplitude modulation has
a) one carrier
b) one carrier with two side band frequencies
c) one carrier with infinite frequencies
d) none of these
Ans:b


11.FM signal is less affected by
a) loss
b) temperature
c) frequency
d) noise

Ans:d


12. ASK is
a) Amplitude shift keying
b) Amplitude shift keyboard
c) Amplitude shine keying
d) none of these
e) Ans:a

13. HPA is
a) high power audio
b) high port audio
c) high power amplifier
d) none of these

Ans:c

14. Word ‘SCANNING’ is used in in
a) telecost
b) telephone
c) radio
d) TV
Ans:d


15 . IF is
a) interference frequency
b) interconnection frequency
c) intermediate frequency
d) none of these

Ans:c


16 . high pass filter attenuates
a) high frequencies
b) low frequencies
c) medium frequencies
d) none of these

Ans:b


17. Low pass filter allows
a) high frequencies
b) medium frequencies
c) zero frequency
d) low frequencies

Ans:d


18. High pass filter allows
a) high frequencies
b) medium frequencies
c) zero frequency
d) low frequencies

Ans:a


19. Primary component of uplink section of satellite is
a) transformer
b) transistor
c) earth station transmitter
d) power station transmitter

Ans:c



20. Non electric signal is converted into electrical signal by
a) transmitter
b) receiver
c) line
d) none of these

Ans:a


21. In order to reduce interference, the signal should be
a) amplified
b) multiplied
c) demodulated
d) modulated

Ans:d


22. An example for an analog signal
a) Sine wave
b) impulse signal
c) sample signal
d) None of these

Ans:a


23. Messages travel from transmitter to receiver with help of
a) Transmitter
b) Receiver
c) channel
d) antennas

Ans:c

24. Bandwidth of FM signal is ---than AM signal
a) lesser
b) either lesser or larger
c) larger
d) none of these

Ans:c

25. In AM modulation ,when the modulation index increases, transmitted power is
a) constant
b) increased
c) decreased
d) none of these

Ans:b