# Physics Class 12th Chapter15 COMMUNICATION SYSTEM VVI Objective Question

Q.1. Sky wave communication is based upon

(A) reflection by ionosphere

(B) absorption by ionosphere

(C) transmission through ionosphere

(D) None of these

Ans :- (A)

Q.2. The process opposite to modulation is

(A) demodulation

(B) transmission

(C) remote sensing

(D) fax

Ans :- (A)

Q.3. A net work within an institution is known as

(A) Internet

(B) local arca network (LAN)

(C) computer’s system

(D) Computers network

Ans :- (B)

Q.4. Which frequency range is used for TV transmission ?

(A) 30 Hz – 300 Hz

(B) 30 kHz – 300 kHz

(C) 30 MHz – 300 MHz

(D) 30 GHz -300 GHz

Ans :- (C)

Q.5. The range of frequencies allotted for FM radio is

(A) 88 to 108 kHz

(B) 88 to 108 MHz

(C) 47 to 230 kHz

(D) 47 to 230 MHz

Ans :- (B)

Q.6. The device that is ‘duplex’ is

(A) TV

(B) mobile

(C) both ‘A’ and ‘B’

(D) None of these

Ans :- (B)

Q.7. In optical fibre communication light source is

(A) Zener diode

(B) laser or LED

(C) photodiode

(D) sodium lamp

Ans :- (B)

Q.8. Which is not an example of analog communication?

(A) FAX

(B) telegraphy

(D) telex

Ans :- (A)

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. The maximum percentage of deformationless modulation is

(A) 100%

(B) 75%

(C) 110%

(D) 50%

Ans :- (A)

Q.11. Which of the following is not a transducer?

(A) land speaker

(B) amplifier

(C) microphone

(D) All the above

Ans :- (B)

Q.12. Broadcasting antennas are generally

(A) omnidirectional type

(B) vertical type

(C) horizontal type

(D) None of these

Ans :- (B)

Q.13. The range of TV transmission can be increased by using

(A) small antennas

(B) tall antennas

(D) None of these

Ans :- (B)

Q.14. The essential components of the communication system are/is

(A) transmitter

(B) channel

(D) All of above

Ans :- (D)

Q.15. Name the device which can represent digital data by analog signals and vice-versa.

(A) Modulation

(B) Demodulation

(C) Modem

(D) None of these

Ans :- (C)

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