276. Find ν₀ for the circuit given below:
     
     
     

1. 1. 4	V
      3

   
   
   

   2. - 2	V
      3

   
   
   

   3. 2	V
      3

   
   
   

   4. – 4	V
      3

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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277. For the circuit shown below relation is:
     
     
     

1. 1. ν₀₁ = ν₀₂

   
   
   

   2. ν₀₁ = – ν₀₂

   
   
   

   3. ν₀ = 2 ν₀₂

   
   
   

   4. 2 ν₀₁ = ν₀₂

   
   
   

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1. View Hint View Answer Discuss in Forum

   From op-amp (1) circuit
   

   VA = Vi		1 +	10
   			1

   
   V_A = 11 V_i ..........................(i)
   from op-amp (2) circuit
   V_o1 = – V_A = – 11 V_i .....................(ii)
   from op-amp (3) circuit
   

   Vo2 = – VA		5		= – VA
   		5

   
   = – 11 V_i .....................(iii)
   Therefore V_o1 = V_o2
   Hence alternative (A) is the correct choice

   
   

   Correct Option: A

   From op-amp (1) circuit
   

   VA = Vi		1 +	10
   			1

   
   V_A = 11 V_i ..........................(i)
   from op-amp (2) circuit
   V_o1 = – V_A = – 11 V_i .....................(ii)
   from op-amp (3) circuit
   

   Vo2 = – VA		5		= – VA
   		5

   
   = – 11 V_i .....................(iii)
   Therefore V_o1 = V_o2
   Hence alternative (A) is the correct choice

   
   

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278. For the circuit given below:
     
     
     

1. 1. R₁ should be high to avoid loading effect

   
   
   

   2. R₁ should be low to avoid loading effect

   
   
   

   3. R_f should be high to avoid loading effect

   
   
   

   4. R_f should be low to avoid loading effect

   
   
   

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1. View Hint View Answer Discuss in Forum

   Since to avoid loading effect input impedance should be high, and in order to active this R_f should be high also.

   Correct Option: C

   Since to avoid loading effect input impedance should be high, and in order to active this R_f should be high also.

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279. If open-loop gain is A_od = 999 in the circuit of the closed-loop gain is:
     
     
     

1. 1. – 0.999

   
   
   

   2. 0.999

   
   
   

   3. 1.001

   
   
   

   4. – 1.001

   
   
   

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1. View Hint View Answer Discuss in Forum

   From given circuit
   V– = V_o
   V+ = V_i
   

   Aod =	Vo	=	Vo
   	V+ – V–		Vi – Vo

   
   

   999 =	Vo
   	Vi – Vo

   
   999 V_i – 999 V_o = V_o
   999 V_i = 1000 V_o
   

   or	Vo	=	999	= 0.999
   	Vi		1000

   
   

   or ACL =	Vo	= 0.999
   	Vi

   Correct Option: B

   From given circuit
   V– = V_o
   V+ = V_i
   

   Aod =	Vo	=	Vo
   	V+ – V–		Vi – Vo

   
   

   999 =	Vo
   	Vi – Vo

   
   999 V_i – 999 V_o = V_o
   999 V_i = 1000 V_o
   

   or	Vo	=	999	= 0.999
   	Vi		1000

   
   

   or ACL =	Vo	= 0.999
   	Vi

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280. The circuit is as shown below:
     The ideal closed-loop voltage gain is:
     
     
     

1. 1. 1

   
   
   

   2. – 1

   
   
   

   3. ∞

   
   
   

   4. 50

   
   
   

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1. View Hint View Answer Discuss in Forum

   From given circuit
   V_o = V_i
   

   or	V0	= 1
   	Vi

   
   

   Correct Option: A

   From given circuit
   V_o = V_i
   

   or	V0	= 1
   	Vi

   
   

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