121. Which one of the following is a transferred electron device?
     

1. 1. BARITT diode
      

   
   
   

   2. IMPATT diode
      

   
   
   

   3. Gunn diode
      

   
   
   

   4. Step recovery diode

   
   
   

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   NA

   Correct Option: C

   NA

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122. The kinetic energy of the beam remains uncharged in the interaction between an electron beam and RF wave in a:
     

1. 1. Multi-cavity klystron
      

   
   
   

   2. Crossed field amplifier
      

   
   
   

   3. Travelling-wave tube
      

   
   
   

   4. Gyrotron

   
   
   

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   NA

   Correct Option: C

   NA

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123. In a rectangular waveguide there is one half-wave variation of electric field across the narrow dimension and two half-wave variations of electric field across the wider dimension. What is dominant mode?
     

1. 1. TM₁₂
      

   
   
   

   2. TE₂₁
      

   
   
   

   3. TE₁₂
      

   
   
   

   4. TM₂₁
      

   
   
   

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   NA

   Correct Option: D

   NA

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124. Arrange in ascending order of fc, cut off frequency of the waveguides in the following modes:
     

1. 1. TE₁₀ < TE₂₀ < TE₀₁ < TM₁₁
      

   
   
   

   2. TE₁₀ < TE₀₁ < TE₂₀ < TM₁₁
      

   
   
   

   3. TM₁₁ < TE₀₁ < TE₂₀ < TE₁₀
      

   
   
   

   4. TE₀₁ < TE₁₀ < TE₂₀ < TM₁₁

   
   
   

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   NA

   Correct Option: B

   NA

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125. In parametric amplifiers, used in microwave communication systems, the amplification is limited by:
     

1. 1. Type of biasing
      

   
   
   

   2. A maximum limit of 10
      

   
   
   

   3. Pump energy
      

   
   
   

   4. Frequency of operation
      

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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