206. Amplifiers for radio receivers are tuned to:

1. 1. 456 Hz

   
   
   

   2. 456 kHz

   
   
   

   3. 456 MHz

   
   
   

   4. 456 GHz

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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207. Which of the following represents the equivalent circuit of a crystal oscillator?
     
     
     

1. 1. figure (a)

   
   
   

   2. figure (b)

   
   
   

   3. figure (c)

   
   
   

   4. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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208. The transformer cores operating at microwave frequency ranges are generally made up of:

1. 1. silicon steel

   
   
   

   2. ferrites

   
   
   

   3. alvino

   
   
   

   4. supermelloy

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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209. Sweep voltage generators, sweep current generators, multivibrators and blocking oscillators can be classified as:

1. 1. negative resistance oscillators

   
   
   

   2. time base tuned collector oscillators

   
   
   

   3. relaxation oscillators.

   
   
   

   4. L–C tuned oscillators.

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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210. Ultra high frequency oscillators work in the range:

1. 1. 20 Hz to 20 kHz

   
   
   

   2. 1 kHz to 30 kHz

   
   
   

   3. 30 kHz to 30 MHz

   
   
   

   4. above 30 MHz

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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