ADVANCE COMMUNICATION SYSYTEM MCQ-4

1. Which of the following radio wave is reflected back to Earth from the ionosphere ?

(A) Sky wava
(B) Ground wave
(C) Space wave
(D) None of these

2. Which of the following wave propagates in the frequency range of 30MHz to 300MHz?

(A) Sky wave
(B) Space wave
(C) Ground wave
(D) None of these

3. Which of the following statement is correct for ground wave propagation ?

(A) It is used for A.M transmission
(B) It is used for F.M transmission
(C) It is used for T.V transmission
(D) None of these

4. Which of the following is lower sideband signal in Amplitude modulation?

(A) m/2 V_c Cos(W_c-W_m)t
(B) m/2 V_c Cos(W_ct)
(C) m/2 V_c Cos(W_mt)
(D) V_c Cos(W_ct)

5. Which of the following broadcast is operated in frequency band of 88 MHz to 108 MHz ?

(A) A.M
(B) F.M
(C) P.M
(D) None of these

6. In Which of the following modulation technique, modulation index depends on frequency of message signal ?

(A) P.M
(B) F.M
(C) A.M
(D) None of these

7. Which of the following noise is generated by automobile, electic motors and switching equipment ?

(A) Thermal noise
(B) Shot noise
(C) Industrial noise
(D) Atmospheric noise

8. Which of the following statements is correct ?

(A) Thermal noise is independent of frequency
(B) Thermal noise is generated in resistance
(C) Industrial noise is a type of internal noise
(D) None of these

9. Which of the following statement is correct for cellular mobile communication ?

(A) Cell size is fixed
(B) Cell size can be increased or decreased
(C) Adjacent cells can not use the same frequency
(D) Both (b) and (c)

10. In hard hand off, a mobile station communicates with

(A) Only one base station
(B) Two base stations
(C) Three base stations
(D) Four base stations

11. Which of the following is the first satellite launched by INDIA ?

(A) ARYABHATTA
(B) APPLE
(C) INSAT-1A
(D) None of thes

12. Which of the following statement is correct for LEO satellite ?

(A) It is located at altitudes between 500 and 2000 Km.
(B) It revolves around the earth in 90 to 120 minutes
(C) Both (a) and (b)
(D) None of these

13. Which of the following statement is correct for optical fiber cable ?

(A) Core is surrounded by cladding
(B) Cladding is more dense compared to core
(C) Cladding is surrounded by core
(D) Core and cladding have same density.

14. Which of the following loss occurs when two optical fibers are joined together to make a longer optical fiber ?

(A) Coupling loss
(B) Spline loss
(C) Micro bending loss
(D) None of these

15. Which of the following device connects transmitter or receiver to the antenna alternately ?

(A) Transponder
(B) Synchronizer
(C) Duplexer
(D) None of these

16. In which of the following RADAR is use ?

(A) Air traffic control
(B) Remote sensing
(C) Military
(D) All of the above

17. Which of the following statement is correct for MTI RADAR ?

(A) It uses dopper effect for its operation
(B) It cannot measure range of a target
(C) It can recognize colour of target
(D) None of these

18. If P(X_i)=1/8, then amount of information I(X_i)

(A) 3 bits
(B) 8 bits
(C) 2 bits
(D) 4 bits

19. Which of the following is one way communication system ?

(A) Pager
(B) Cellular phone
(C) Fax machine
(D) None of these

20. Which of the following factor limits the channel capacity C?

(A) Bandwidth of channel
(B) Noise signal
(C) Both (a) and (b)
(D) None of these