131. Which one of the following modes of transmission will not be supported by a rectangular waveguide?
     

1. 1. TE₁₀
      

   
   
   

   2. TM₁₁
      

   
   
   

   3. TE₁₁
      

   
   
   

   4. TM₁₀

   
   
   

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   NA

   Correct Option: D

   NA

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132. Rain drop attenuation in most microwave communication links is caused due to:
     

1. 1. Scattering of microwaves by water drops of specific size
      

   
   
   

   2. Scattering of microwaves by a collection of droplets acting as a single body
      

   
   
   

   3. Absorption of microwave by water and consequent heating of the liquid
      

   
   
   

   4. Absorption of microwaves by water-vapour in the atmosphere

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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133. The semiconductor diode which can be used in switching circuits at microwave range is:
     
     

1. 1. PIN diode
      

   
   
   

   2. Tunnel diode
      

   
   
   

   3. Varactor diode
      

   
   
   

   4. Gunn diode

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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134. HEMT used in the microwave circuit is a:
     

1. 1. Source
      

   
   
   

   2. High power amplifier
      

   
   
   

   3. Detector
      

   
   
   

   4. Low noise amplifier

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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135. Microwave antenna aperture efficiency depends on:
     

1. 1. Feed pattern
      

   
   
   

   2. Antenna aperture
      

   
   
   

   3. Surface losses

   
   
   

   4. Low side lobe level

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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