91. In phase-shift SSB modulator, the input signals one of the balanced modulators are phase-shifted by—
    

1. 1. 45°
      

   
   
   

   2. 90°
      

   
   
   

   3. 180º
      

   
   
   

   4. 30°

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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92. The SSB modulator is known as—
    

1. 1. Balanced modulator
      

   
   
   

   2. Product modulator
      

   
   
   

   3. Amplitude modulator
      

   
   
   

   4. None of these
      

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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93. The advantage of SSB-SC system is that it provides—
    

1. 1. Higher frequency of transmission
      

   
   
   

   2. Better quality of communication
      

   
   
   

   3. Simpler and inexpensive circuitry
      

   
   
   

   4. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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94. The filter required to obtain SSB from DSB signal is—
    

1. 1. LPF
      

   
   
   

   2. HPF
      

   
   
   

   3. BPF
      

   
   
   

   4. None

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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95. An AM wave
    10[1 + 0·6 cos 2π 10³t] cos 2π 10⁶t
    is to be detected by a linear diode detector, the value of the time constant is—
    

1. 1. 0.17 ms
      

   
   
   

   2. 1.7 ms
      

   
   
   

   3. 0.212 ms
      

   
   
   

   4. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   The given AM wave is
   s(t) = 10[1 + 0·6 cos 2π 10³t] cos 2π 10⁶t
   Here μ = 0·6 and ω_m = 2π·10³
   The required condition for the detector output is to follow the envelop all the times is
   

   RC ≤	1	√	1 − μ2
   	ωm		μ2

   
   or
   

   RC ≤	1	√	1 − (0.6)2
   	2π103		(0.6)2

   
   or τ ≤ 0.212 ms
   or
   

   RC ≤	1.33
   	2π103

   
   Hence alternative (C) is the correct choice.

   Correct Option: C

   The given AM wave is
   s(t) = 10[1 + 0·6 cos 2π 10³t] cos 2π 10⁶t
   Here μ = 0·6 and ω_m = 2π·10³
   The required condition for the detector output is to follow the envelop all the times is
   

   RC ≤	1	√	1 − μ2
   	ωm		μ2

   
   or
   

   RC ≤	1	√	1 − (0.6)2
   	2π103		(0.6)2

   
   or τ ≤ 0.212 ms
   or
   

   RC ≤	1.33
   	2π103

   
   Hence alternative (C) is the correct choice.

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