Friday, May 15, 2015

Basic Electronics and Comm Questions Objective

Basic Electronics and Comm Questions Objective
Electronics Communications Interview Questions and Answers
1.Communication is a process of
a) transfer of information
b) transfer of energy
c) transfer of channel
d) none of these
Ans:a
2. An example of communication service
a) printer
b) television
c) both(a)&(b)
d) none of these
Ans:b
3. Channel is
a) medium
b) signal
c) carrier
d) none of these
Ans:a
4. Analog signal varies with
a) sampling time
b) time continuously
c) sampling frequency
d) none of these
Ans:b
5. Discrete signal is represented by
a) coding
b) modulation
c) demodulation
d) sequence of samples
Ans:d
6. Carrier signal has
a) constant magnitude
b) constant frequency
c) variable frequency
d) variable time
Ans:a
7.Modulating signal has
a) low frequency
b) low modulation
c) high frequency
d) none of these
Ans:a
8. Modulation index is
a) Vm/Vc
b) Vc/Vm
c) Vm/Ic
d) None of these
Ans:a
9. fc +fm is
a) upper band frequency
b) lower band frequency
c) mid band frequency
d) none of these
Ans:a
10. fc –fm is
a) upper band frequency
b) lower band frequency
c) mid band frequency
d) none of these
Ans:b
11.In amplitude modulation, frequency is
a) constant
b) zero
c) variable
d) one
Ans:a
12. In amplitude modulation, amplitude is
a) constant
b) zero
c) variable
d) none of these
Ans:c
13.In frequency modulation, frequency is
a. constant
b. zero
c. variable
d.one
Ans:c
14. In frequency modulation, amplitude is
a.constant
b.zero
c.one
d.variable
Ans:a
15. 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
16. 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
17.FM signal is less affected by
a) loss
b) temperature
c) frequency
d) noise
Ans:d
18. FSK is
a) frequency shift keying
b) frequency shine keying
c) frequency shine keyboard
d) none of these
Ans:a
a) Amplitude shift keying
b) Amplitude shift keyboard
c) Amplitude shine keying
d) none of these
e) Ans:a
20. HPA is
a) high power audio
b) high port audio
c) high power amplifier
d) none of these
Ans:c
21. Word ‘SCANNING’ is used in in
a) telecost
b) telephone
d) TV
Ans:d
22. The frequency range of 1GHZ to 30GHZ are referred as
a) sound waves
b) micro waves
c) mini waves
d) none of these
Ans:b
23 . IF is
a) interference frequency
b) interconnection frequency
c) intermediate frequency
d) none of these
Ans:c
24. Low pass filter attenuates
a) high frequencies
b) low frequencies
c) medium frequencies
d) none of these
Ans:a
25 . high pass filter attenuates
a) high frequencies
b) low frequencies
c) medium frequencies
d) none of these
Ans:b
26. Low pass filter allows
a) high frequencies
b) medium frequencies
c) zero frequency
d) low frequencies
Ans:d
27. High pass filter allows
a) high frequencies
b) medium frequencies
c) zero frequency
d) low frequencies
Ans:a
28. Primary component of uplink section of satellite is
a) transformer
b) transistor
c) earth station transmitter
d) power station transmitter
Ans:c
29. Micro wave communication is used in
a) TNEB
b) telephone networks
c) industries
d) none of these
Ans:b
30. Non electric signal is converted into electrical signal by
a) transmitter
c) line
d) none of these
Ans:a
31. In order to reduce interference, the signal should be
a) amplified
b) multiplied
c) demodulated
d) modulated
Ans:d
32. An example for an analog signal
a) Sine wave
b) impulse signal
c) sample signal
d) None of these
Ans:a
33. Messages travel from transmitter to receiver with help of
a) Transmitter
c) channel
d) antennas
Ans:c
34. Bandwidth of FM signal is ---than AM signal
a) lesser
b) either lesser or larger
c) larger
d) none of these
Ans:c
35. In AM modulation ,when the modulation index increases, transmitted power is
a) constant
b) increased
c) decreased
d) none of these
Ans:b
36. In FM modulation ,when the modulation index increases, transmitted power is
a) constant
b) increased
c) decreased
d) none of these
Ans:a
37. Sound signalsin TV are
a) amplitude modulated
b) dc modulated
c) frequency modulated
d) a and c
Ans:c
38. Video signals in TV are
a) amplitude modulated
b) de modulated
c) frequency modulated
d) none of these
Ans:a
39. In optical communication, carrier is
a) electromagnetic waves in optical frequency
b) electromagnetic waves in maximum frequency
c) electromagnetic waves in minimum frequency
d) none of these
Ans:a
40. Optical detector is
a) diode
b) PIN photo diode
c) transistor
d) none of these
Ans:b
41.Optical fibre has---diameter
a.small
b.large
c.zero
d.none of these
Ans:a
42. Optical fibre is fabricated by
a) glass
b) copper
c) aluminium
d) none of these
Ans:a
43.An earth station receiver consists of
a.RF to IF down converter
b. IFto RF converter
c.either (a)&(b)
d.none of these
Ans:a
44. An earth station transmitter consists of
a.RF to IF down converter
b. IFto RF converter
c. either (a)&(b)
d.none of these
Ans:b
45.VHF is
a.very low frequency
b.very high frequency
c.very hot frequency
d.none of these
Ans:b
46. TRF is nothing but
d.none of these
Ans:b
47.which one of the following is the type of ‘superheterodyning’
b.TV
Ans:c
48.AFC is nothing but
a.Audio frequency control
b.Automatic frequency control
c.Amplitude frequency control
d.none of these
Ans:b
49.The maximum power in AM,when modulation index is
a.0
b.0.5
c.0.7
d.1
Ans:d
50.Primary colours are
a.red,blue.green
b.green,white.blue
c.blue,red.yellow
d.none of these
Ans:a