1. Who undertook the first space walk and in which year ?
(A) Leonov, 1965
(B) Neil Armstrong, 1969
(C) Rakesh Sharma, 1998
(D) None of these
2. The term used “to collect the information about an object and a place without physical contact” is called :
(A) modulation
(B) communication
(C) amplification
(D) remote sensing
3. The velocity of electromagnetic wave is :
(A) 3 x 105 ms-1
(B) 3 x 106 ms-1
(C) 3 x 108 ms-1
(D) 3 x 1010 ms-1
4. The audio frequencies range from :
(A) 20 Hz to 20,000 kHz
(B) 20 Hz to 20 kHz
(C) 20 kHz to 20,000 kHz
(D) None of these
5. The wavelength of a wave of frequency 10 kHz is :
(A) 30 m
(B) 300 m
(C) 30 km
(D) 300 km
6. The area served by an antenna of height 100 m is :
(A) 109 m2
(B) 4 x 109 m2
(C) 6 x 109 m2
(D) 8 x 1010 m2
7. Which of the following is not transducer ?
(A) Loudspeaker
(B) Amplifier
(C) Microphone
(D) All
8. The space waves which are affected seriously by atmospheric conditions are :
(A) MF
(B) HUF
(C) VHF
(D) UHF
9. An antenna is :
(A) Inductive
(B) Capacitive
(C) Resistive
(D) A transformer
10. Broadcasting antenna are generally :
(A) Ommi directional type
(B) Vertical type
(C) Horizontal type
(D) None
11. The modulation index in amplitude modulation is :
(A) Always zero
(B) Between 0 and 1
(C) Between 1 and ∞
(D) None of these
12. The output of a digital computer is an example of :
(A) digital signal
(B) analog signal
(C) both (A) and (B)
(D) neither (A) nor (B)
13. Name the man who was first to place his foot on the moon and in which year :
(A) Neil Armstrong, 1969
(B) James Van Allen, 1971
(C) Leonov, 1965
(D) None of these
14. A microphone converts :
(A) sound signals into electrical signals
(B) electrical signals into sound signals
(C) both (A) and (B)
(D) Neither (A) nor (B)
15. A loudspeaker converts :
(A) electrical signals into sound signals
(B) sound signals into electrical signals
(C) both (A) and (B)
(D) neither (A) nor (B)
16. The sound produced by a tuning fork is a sort of:
(A) analog signal
(B) digital signal
(C) both (A) and (B)
(D) neither (A) nor (B)
17. The length of a half wave dipole at 30 mega hertz is :
(A) 5 m
(B) 10 m
(C) 25 m
(D) 80 m
18. In space communication, the sound waves can be sent from one place to another :
(A) through space
(B) through wires
(C) by superimposing it on undamped electro magnetic waves
(D) by superimposing it on damped electro magnetic waves
19. The output of a digital computer is an example of:
(A) digital signal
(B) analog signal
(C) both (A) and (B) above
(D) neither (A) nor (B)
20. Which is more advantageous ?
(A) analog data communication
(B) digital data communication
(C) both (A) and (B) are equally good
(D) depends on the situation
21. A byte is a string of n bits. Then n equals :
(A) 8
(B) 6
(C) 4
(D) 2
22. When the modulation percentage is 75, an AM transmitter produces 10 kW. How much of this is carrier power ?
(A) 10 kW
(B) 12.30 kW
(C) 7.5 kW
(D) 7.81 kW
23. The range of frequencies allotted for commercial FM radio broadcast is :
(A) 88 to 108 MHz
(B) 88 to 108 kHz
(C) 8 to 889 MHz
(D) None of these
24. The range of frequencies allotted for commercial VHF TV broadcast is :
(A) 76-88 MHz
(B) 54-72 MHz
(C) 174-216 MHz
(D) None of these
25. The range of frequencies allotted for commercial UHF TV broadcast is :
(A) 76-88 MHz
(B) 54-72 MHz
(C) 174-216 MHz
(D) None of these
26. Basically a communication system is a:
(A) transmitter
(B) receiver
(C) messenger
(D) None of these