A Best Way To Crack Gorenment Job Exams

ECE Objective Questions { Digital Communication System }



29. A carrier is amplitude-modulated by two sine waves of different frequencies with modulation indices 0.3 and 0.4. The resulting overall modulation index is
A.0.5
B.0.7
C.0.1
D.0.01

30. In television transmission, picture signals are transmitted by
A. AM
B. FM
C. PCM
D. PAM

31. In a pulse transmission system, the error rate
A. is independent of noise at SIN ratio above 20 dB
B. increases as SIN ratio increases
C. decreases as SIN ratio increases
D. none of above

32. Increasing the height of the radiating antenna, the coverage area of a TV station would
A. increase
B. decrease
C. not change
D. none of above

33. PPM is a?modulation technique.
A. linear
B. analog
C. digital
D. frequency

34. Intersymbol interference is a problem in transmission.
A. AM
B. FM
C. PCM
D. PAM

35. In a radio receiver
A. all stages contribute equally to noise
B. RF stage has no effect on SIN ratio
C. mixer stage contributes most of the noise generated
D. none of the above

Page 5 of 37

« 3 4  5  67 »

Subjects