NCERT Class 12 MCQ Quiz Hub

1. Who undertook the first space walk and in which year?
Leonov 1965
Neil Armstrong, 1969
Rakesh Sharma. 1998
None of the above these

2. The term used “to collect the information about an object and a place without physical contact” is called :
modulation
communication
amplification
remote sensing

3. The audio frequencies range from:
20 Hz to 20.000 kHz
20 Hz to 20 kHz
20 kHz to 20.000 kHz
None of the these

4. The wavelength of a wave of frequency 10 kHz is:
30 m
300 m
30 km
300 km

5. Which of the following is not transducer?
Loudspeaker
Amplifier
Microphone
All

6. The space waves which are affected seriously by atmospheric conditions are:
MF
HUF
VHF
UHF

7. An antenna is:
Inductive
Capacitive
Resistive
A transformer

8. Broadcasting antenna are generally:
Ommi directional type
Vertical type
Horizontal type
None

9. The modulation index in amplitude modulation is:
Always zero
Between 0 and 1
Between 1 and ∞
None of these

10. The output of a digital computer is an example of:
digital signal
analog signal
both (a) and (b)
neither (a) nor (b)

11. Name the man who was first to place his foot on the moon and in which year:
Neil Armstrong, 1969
James Van A lien, 1971
Leonov, 1965
None of the these

12. A microphone converts:
sound signals into electrical signals
electrical signals into sound signals
both (a) and (b)
Neither (a) nor (b)

13. A loudspeaker converts:
electrical signals into sound signals
sound signals into electrical signals
both (a) and (b)
neither (a) nor (b)

14. The length of a half wave dipole at 30 mega-hertz is:
5 m
10 m
25 m
80 m

15. In space communication, the sound waves can be sent from one place to another:
through space
through wires
by superimposing it on undamped electro-magnetic waves
by superimposing it on damped electro-magnetic waves

16. Which is more advantageous?
analog data communication
digital data communication
both (a) and (b) are equally good
depends on the situation

17. Communication channel consists of:
transmission line only
optical fibre only
free space only
All the above

18. AM is used for broadcasting because:
it is more noise immune than other modulation system
it requires less transmitting power compare with other systems
its use avoids receiver complexity
No other modulation system can provide the necessary bandwidth faithful transmission

19. Digital signals:
represents values as discrete steps
Do not represents values as discrete steps
represent values steps
represent random steps

20. Increase in frequency deviation results into:
increase in noise of FM receiver
decrease in noise of AM receiver
increase in noise of Am receiver
decrease in noise of FM receiver