181. Modulation index of FM signal—
     

1. 1. 2.75
      

   
   
   

   2. 13.75
      

   
   
   

   3. 275
      

   
   
   

   4. 27.5

   
   
   

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1. View Hint View Answer Discuss in Forum

   β =	Δf	=	0.11 × 106	= 27.5
   	fm		4 × 103

   
   

   Correct Option: D

   β =	Δf	=	0.11 × 106	= 27.5
   	fm		4 × 103

   
   

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182. Frequency deviation of AM signal—
     

1. 1. 0.11 MHz
      

   
   
   

   2. 0.22 MHz
      

   
   
   

   3. 11 kHz
      

   
   
   

   4. 22 kHz

   
   
   

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1. View Hint View Answer Discuss in Forum

   Subtracting equation (i) and (ii) we get
   2Δf_m = 0·22 MHz
   or
   Δf_m = 0·11 MHz

   Correct Option: A

   Subtracting equation (i) and (ii) we get
   2Δf_m = 0·22 MHz
   or
   Δf_m = 0·11 MHz

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183. Carrier frequency—

1. 1. 53.6035 MHz

   
   
   

   2. 107.207 MHz

   
   
   

   3. 5360 kHz

   
   
   

   4. 1072 kHz

   
   
   

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1. View Hint View Answer Discuss in Forum

   Given, f_c + Δ f_m = 107·218 MHz …(i)
   f_c + Δf_m = 107·196 MHz …(ii)
   adding equations (i) and (ii),
   we get
   2f_c = (107·218 + 107·196) MHz
   or
   f_c = 107·207 MHz

   Correct Option: B

   Given, f_c + Δ f_m = 107·218 MHz …(i)
   f_c + Δf_m = 107·196 MHz …(ii)
   adding equations (i) and (ii),
   we get
   2f_c = (107·218 + 107·196) MHz
   or
   f_c = 107·207 MHz

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184. The carrier swing—
     

1. 1. 0.22 MHz
      

   
   
   

   2. 0.11 MHz
      

   
   
   

   3. 22 kHz
      

   
   
   

   4. 11 kHz

   
   
   

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1. View Hint View Answer Discuss in Forum

   Carrier swing = 107.218 – 107.196 = 0.22 MHz

   Correct Option: A

   Carrier swing = 107.218 – 107.196 = 0.22 MHz

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185. The modulating frequency in frequency modulation is increased from 10 kHz to 20 kHz. The bandwidth is—

1. 1. doubled
      

   
   
   

   2. halved
      
      

   
   
   

   3. increases by 20 kHz
      

   
   
   

   4. increased tremendously

   
   
   

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1. View Hint View Answer Discuss in Forum

   Since, BW = 2(Δf + f_m)
   When f_m increased from 10 kHz to 20 kHz i.e. 10 kHz BW increased by 20 kHz.

   Correct Option: C

   Since, BW = 2(Δf + f_m)
   When f_m increased from 10 kHz to 20 kHz i.e. 10 kHz BW increased by 20 kHz.

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