386. In the circuit shown the zener voltage V_Z1 = V_Z2 = 5 volts, V_γ = 0.6, V₀ is the output—
     
     
     

1. 1. For | V_i | ≤ 5.6 volt, V₀ = V_i

   
   
   

   2. For | V_i | ≤ 10 volt, V₀ = V_i

   
   
   

   3. For | V_i | > 5.6 volt, V₀ = V_i

   
   
   

   4. V₀ = 5.6 volt for all V_i

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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387. Of the four biasing circuits shown in figure for a BJT, indicate the one which can have maximum bias stability—

1. 1. 

   
   
   

   2. 

   
   
   

   3. 

   
   
   

   4. 

   
   
   

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1. View Hint View Answer Discuss in Forum

   We know that potential divider biasing always provide maximum bias stability than any other biasing circuit.

   Correct Option: A

   We know that potential divider biasing always provide maximum bias stability than any other biasing circuit.

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388. For good stabilised biasing of the transistor for the CE amplifier of figure we should have—

1. 1. 	RE	<< 1
      	RB

   
   
   

   2. 	RE	>> 1
      	RB

   
   
   

   3. 	RB	<< hFE
      	RE

   
   
   

   4. >> h_FE

   
   
   

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   	RE	>> 1 for good stability
   	RB

   Correct Option: B

   	RE	>> 1 for good stability
   	RB

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389. A source follower (using an FET) usually has a voltage gain which is—

1. 1. Greater than +100

   
   
   

   2. Slightly less than unity but positive

   
   
   

   3. Exactly unity but negative

   
   
   

   4. About –10

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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390. An amplifier without feedback has a gain of 1000. The gain with a negative feedback of 0.009 is—

1. 1. 100

   
   
   

   2. 10

   
   
   

   3. 900

   
   
   

   4. 125

   
   
   

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1. View Hint View Answer Discuss in Forum

   Af =	A	where Af = gain after feedback
   	1 + Aβ

   
   

   =	1000	A = gain before feedback
   	1 + 1000 × .009

   
   

   =	1000	= 100 β = negative feedback factor
   	1 + 9

   
   Hence alternative (A) is the correct answer.
   
   

   Correct Option: A

   Af =	A	where Af = gain after feedback
   	1 + Aβ

   
   

   =	1000	A = gain before feedback
   	1 + 1000 × .009

   
   

   =	1000	= 100 β = negative feedback factor
   	1 + 9

   
   Hence alternative (A) is the correct answer.
   
   

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