36. Thermal runaway of thyristor occurs—
    

1. 1. When the load is suddenly withdrawn
      

   
   
   

   2. If the temperature of thyristor is high
      

   
   
   

   3. In case forward anode to cathode voltage is greater than the forward breakdown voltage
      

   
   
   

   4. In case Gate current is high

   
   
   

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   NA

   Correct Option: B

   NA

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37. An ideal rectifier should have—
    1. Harmonics factor = 1
    2. Transformer utilisation factor = 1
    3. Efficiency = 100%
    4. Effective value of AC component of o/p voltage = 0
    5. The I/P power factor = 1
    The correct statements are:
    

1. 1. 1 and 2 only
      

   
   
   

   2. 1, 2 and 3 only
      

   
   
   

   3. 2, 3 and 4 only
      

   
   
   

   4. 2, 3 and 5 only

   
   
   

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   NA

   Correct Option: D

   NA

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38. Which of the following thyristors are Gate turned OFF device?
    1. Gate turned off thyristor
    2. Static induction thyristor
    3. MOS controlled thyristor
    

1. 1. 1 only
      

   
   
   

   2. 2 only
      

   
   
   

   3. 1 and 2 only
      

   
   
   

   4. 1, 2 and 3 only

   
   
   

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   NA

   Correct Option: D

   NA

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39. An ideal rectifier should have transformer utilisation factor (TUF) of 1. If the actual TUF is 3·5, It shows that—
    

1. 1. Diode is under loaded
      

   
   
   

   2. The transformer must be 3·5 times large
      

   
   
   

   3. The transformer should be only 1/3·5 times the ideal size
      

   
   
   

   4. The ripple factor is low

   
   
   

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   NA

   Correct Option: B

   NA

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40. In dielectric heating. It the capacitor is loss free. The heat produced will be—
    

1. 1. Zero
      

   
   
   

   2. ∞
      

   
   
   

   3. Proportional to the value of capacitor
      

   
   
   

   4. Proportional to the frequency of capacitor

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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