Analog Communications Mid - I, September - 2014

1.The maximum power in AM,when modulation index is
  • 0
  • 0.5
  • 0.7
  • 1
Answer: D
2.Bandwidth of vestigial side band modulation is
  • w
  • 2w
  • w + fv
  • none of the above
Answer: C
3.Non electric signal is converted into electrical signal by
  • transmitter
  • receiver
  • line
  • none of these
Answer: A
4.frequency modulation has
  • one carrier
  • one carrier with two side band frequencies
  • one carrier with infinite frequencies
  • none of these
Answer: C
5.The efficiency of Amplitude modulation is
  • 33.3%
  • 66.6%
  • 81.2%
  • none of the above
Answer: A
6.If the modulation index of an AM wave is changed from 0 to 1,then the transmitted power will be
  • increased by 50%
  • increased by 75%
  • increased by 100%
  • None
Answer: A
7.Carrier signal has
  • constant magnitude
  • constant frequency
  • variable frequency
  • variable time
Answer: A
8.fc + fm is
  • upper band frequency
  • lower band frequency
  • mid band frequency
  • none of these
Answer: A
9.In frequency modulation, transmission power is
  • constant
  • zero
  • one
  • variable
Answer: A
10.What are the types of ANGLE MODULATION
  • AM & FM
  • FM & PM
  • AM & PM
  • AM, FM & PM
Answer: B
11.Video signals in TV are ______________ modulated.
Answer: Amplitude
12.In AM modulation ,when the modulation index increases, transmitted power is _______________ .
Answer: Increased
13.Messages travel from transmitter to receiver with help of _________________________ .
Answer: Channel
14.In order to reduce interference, the signal should be _______________ .
Answer: Modulated
15.Communication is a process of __________________ .
Answer: Transfer of information
16.Theoretical bandwidth of FM wave is __________________
Answer: , infinity
17.Modulating signal has _____________ frequency.
Answer: Low frequency
18.Modulation index is = ________________ .
Answer: Vm / Vc
19.In amplitude modulation, frequency is ___________________ .
Answer: Constant
20.Total power of any signal is equal to _____________ .
Answer: PT = Pc[1 + 2 / 2]