16. Through which mode of propagation the radio waves can be sent from one place to another ?

1. 1. Ground wave propagation

   
   
   

   2. Sky wave propagation

   
   
   

   3. Space wave propagation

   
   
   

   4. All of the above

   
   
   

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   NA

   Correct Option: D

   NA

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17. The resistance of a pn junction in forward bias is

1. 1. Zero

   
   
   

   2. Low

   
   
   

   3. High

   
   
   

   4. Infinite

   
   
   

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   NA

   Correct Option: B

   NA

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18. A typical Example of a semiconductor is

1. 1. Platinum

   
   
   

   2. Germanium

   
   
   

   3. Quartz

   
   
   

   4. Mica

   
   
   

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   NA

   Correct Option: B

   NA

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19. Antenna is

1. 1. Inductive

   
   
   

   2. Capacitive

   
   
   

   3. Resistive its resonant frequency

   
   
   

   4. Resistive at resonant frequency

   
   
   

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   NA

   Correct Option: A

   NA

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20. The size of atomic nucleus is of the order of

1. 1. 10^-15 m

   
   
   

   2. 10^-12 m

   
   
   

   3. 10^-14 m

   
   
   

   4. 10^-10 m

   
   
   

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   NA

   Correct Option: A

   NA

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