41. The biggest disadvantage of PCM is—
    

1. 1. Its inability to handle analog signals
      

   
   
   

   2. The high error rate which its quantizing noise introduces
      

   
   
   

   3. Its incompatibility with TDM
      

   
   
   

   4. The large bandwidths that are required for it

   
   
   

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   NA

   Correct Option: D

   NA

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42. Companding is used—
    

1. 1. To overcome quantizing noise in PCM
      

   
   
   

   2. In PCM transmitters, to allow amplitude limiting in the receivers
      

   
   
   

   3. To protect small signals in PCM from quantizing distortion
      

   
   
   

   4. In PCM receivers, to overcome impulse noise

   
   
   

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   NA

   Correct Option: C

   NA

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43. Indicate which of the following pulse modulation systems is analog?
    

1. 1. PCM
      

   
   
   

   2. Differential PCM
      

   
   
   

   3. PWM
      

   
   
   

   4. Delta

   
   
   

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   NA

   Correct Option: C

   NA

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44. The Hartley-Shannon theorem sets a limit on the—
    

1. 1. Highest frequency that may be sent over a given channel
      

   
   
   

   2. Maximum capacity of a channel with a given noise level
      

   
   
   

   3. Maximum number of coding levels in a channel with a given noise level
      

   
   
   

   4. Maximum number of quantizing levels in a channel of a given bandwidth

   
   
   

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   NA

   Correct Option: B

   NA

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45. The modulation system inherently most noise-resistant is—
    

1. 1. SSB, suppressed-carrier
      

   
   
   

   2. Frequency modulation
      

   
   
   

   3. Pulse-position modulation
      

   
   
   

   4. Pulse-code modulation

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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