Q.1. The optical fibre works on the principle of
(A) Scattering
(B) Refraction
(C) Dispersion
(D) Total internal reflection
Ans:- (D)
Q.2. The value of amplitude modulation index is
(A) always zero
(B) between 1 and ∞
(C) between 0 and 1
(D) always ∞
Ans:- (C)
Q.3. Which frequency range is used for TV transmission ?
(A) 30Hz-300Hz
(B) 30kHz-300kHz
(C) 30MHz-300MHz
(D) 30GHz-300GHz
Ans:- (C)
Q.4. The height of a TV transmission tower at any place on the surface of the earth is 245 m. The maximum distance up to which transmission of tower will reach is
(A) 245 m
(B) 245 km
(C) 56 km
(D) 112 km
Ans:- (C)
Q.5. Sky wave communication is based on
(A) reflection by ionosphere
(B) absorption by ionosphere
(C) transmission through ionosphere
(D) none of these
Ans:- (A)
Q.6. In optical fibre communication light source is
(A) zener diode
(B) laser or LED
(C) photodiode
(D) sodium lamp
Ans:- (B)
Q.7. Name the types of communication system according to the mode of transmission.
(A) Analog of communication system
(B) Digital communication system
(C) Both A and B
(D) none of these
Ans:- (C)
Q.8. A network within an institution is known as
(A) internet
(B) local area network (LAN)
(C) Computer system
(D) computers network
Ans:- (B)
Q.9. For radio waves ionosphere acts as a
(A) rarer medium
(B) denser medium
(C) free space
(D) dielectric medium
Ans:- (A)
Q.10. Which is not an example of analog communication ?
(A) FAX
(B) telegraphy
(C) Radar
(D) telex
Ans:- (A)
Q.11. Name the device which can represent digital data by analog signals and vice-versa.
(A) Modulation
(B) Demodulation
(C) Modern
(D) none of these
Ans:- (C)
Q.12. The essential components of the communication system are
(A) transmitter
(B) channel
(C) receiver
(D) all of above
Ans:- (D)
Q.13. The range of TV transmission can be increased by using
(A) small antennas
(B) tall antennas
(C) radio waves
(D) none of these
Ans:- (B)
Q.14. The device that is ‘duplex’ is
(A) TV
(B) mobile
(C) both ‘A’ and ‘B’
(D) none of these
Ans:- (B)
Q.15. The process opposite to modulation is
(A) Demodulation
(B) transmission
(C) remote sensing
(D) Fax
Ans:- (A)
Q.16. For television broadcast which type of modulation is used for audio signal ?
(A) amplitude modulation
(B) pulse modulation
(C) frequency modulation
(D) none of these
Ans:- (C)
Q.17. The loss of strength of a signal as it propagates through the communication channel is called
(A) antenna
(B) digital system
(C) attenuation
(D) none of these
Ans:- (C)
Q.18. The maximum percentage of deformationless modulation is
(A) 100%
(B) 75%
(C) 110%
(D) 50%
Ans:-(A)
Q.19 Which of the following is not a transducer ?
(A) land speaker
(B) amplifier
(C) microphone
(D) all of the above
Ans:- (B)
Q.20. Broadcasting antennas are generally
(A) Omni directional type
(B) vertical type
(C) horizontal type
(D) none of these
Ans:- (B)