151. The modes in a reflex klystron:
     

1. 1. Give the same frequency but different transit times

   
   
   

   2. Result from excessive transit time across the resonator gap
      

   
   
   

   3. Are caused by spurious frequency modulation
      

   
   
   

   4. Are just for theoretical considerations

   
   
   

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   NA

   Correct Option: A

   NA

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152. The transmit time in the repeller space of a reflex klystron must be:
     

1. 1. n cycles

   
   
   

   2. 	n +	1		cycles
      		4

      
      

   
   
   

   3. 	n +	3		cycles
      		4

   
   
   

   4. 	n +	1		cycles
      		2

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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153. A reflex klystron functions as:
     

1. 1. Microwave oscillator
      

   
   
   

   2. Microwave amplifier
      

   
   
   

   3. Both as microwave amplifier and oscillator
      

   
   
   

   4. A high gain cavity

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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154. Multicavity klystron:
     

1. 1. Is not a microwave device

   
   
   

   2. In not a good low level amplifier because of noise

   
   
   

   3. Is not suited for pulse operation

   
   
   

   4. Has a high repeller voltage to ensure small transit time

   
   
   

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   NA

   Correct Option: B

   NA

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155. Dither-tuned magnetrons:
     

1. 1. Can be easily jammed
      

   
   
   

   2. Can send pulses on one frequency only
      

   
   
   

   3. Operates on a fixed frequency
      

   
   
   

   4. May be conventional or coaxial

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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