IIT JEE MCQ Quiz Hub

1. The dc voltage applied at each station in case of coaxial cables is
1400 V
1300 V
1350 V
1250 V

2. The maximum frequency at which coaxial cable operates
2500 mc/s
2000 mc/s
3000 mc/s
300 mc/s

3. Process of sending and receiving the information with the help of some suitable system is called
Communication
Tranxmission
Fax
Modem

4. Which of the following pair belongs to the same communication system
Telephony Fax
Telegraphy E-mail
Teleprinting
Communication satellite Telemetry Mobile Phone

5. Modem is a device which performs
Modulation
Demodulation
Rectification
Modulation and demodulation

6. A certain transmitter radiates 9 kW of power with carrier unmodulated and 10.125 kW when the carrier is modulated. The modulation index is
60%
55%
40%
50%

7. The satellite that is used in ship to shore and shore to ship communication is
Comsat
Marisat
Telstar
Intelstar

8. Electronic transmission of a document to a distant place via telephone line is called
Fax
Modem
E-mail
Telephone

9. Which of the following is use for analogue to digital conversion ?
Amplitude modulation
Pulse code modulation
Frequency modulation
Phase modulation

10. If the wavelength of the electromagnetic radiations is doubled frequency of the electromagnetic radiations will be
same as earlier
half the earlier
double the earlier
four times the earlier

11. The optical source is used to
convert electrical energy into optical energy
deted the signal
demodulate the electrical signal
All of the above

12. The maximum usable frequency in F-layer with original frequency of 50 MHz will be
181 MHz
150 MHz
250 MHz
300 MHz

13. The frequency of a wave propagating in D-region having refractive index is 0.5 is
400 Kc/s
300 Kc/s
207.33 Kc/s
None of these

14. For a FM wave the carrier is 160 MHz modulating frequency is 15 kHz and frequency deviation of 1 MHz if modulating frequency is doubled the band width will be
5 MHz
3 MHz
2 MHz
1 MHz

15. If total power content of an AM wave is 2.64 kW at 80% modulation then power content of each side band are
1.32 kW
2.64 kW
660 watt
320 watt

16. Total power content of an AM waves is 1500 watt. For a 100% modulation power content of carrier should be
500 watt
1000 watt
1500 watt
None of these

17. A charge having oscillating frequency 2 MHz. The wavelength will be None of these
150 KM
200 KM
250 KM
None of these

18. A band width of 15 MHz is available for transmission. If maximum signal frequency used for modulating the corrier is 15 kHz then low number of stations which can broadcast without any inference with each other ) in this band is
300
400
457
500

19. The UHF band ranges from
30 to 300 MHz
30 to 3000 MHz
20 to 2000 MHz
30 to 300 KHz

20. A sinusoidal carrier wave of frequency of 15 MHz is modulated by audio signal of frequency of 5 KHz then upper frequency component of the resultant modulated wave is
15 MHz
10 MHz
15.005 MHz
14.995 MHz

21. For a FM wave the carrier is 160 MHz modulating frequency is 15 kHz and frequency deviation of 1 MHz. The band width required is
2 MHz
1 MHz
20 KHz
10 MHz

22. The glass of optical fibre has refractive index 1.6 and is clad with another glass of refractive index 1.52. The numerical aperture will be
0.499
0.459
0.0625
0.352

23. A modulated wave has maximum amplitude of 750 mV and minimum amplitude of 250 mV. Then percentage modulation is
33%
50%
75%
100%

24. If a carrier wave of amplitude to mV is modulated by an audio signal of amplitude 2 mV then amplitude of LSF and USF is given by
0.2 mV
0.5 mV
1 mV
2 mV