6. The common mode voltage is completely alternated at the out put of the differential amplifier shown in the figure, if
   
   

1. 1. R₁ + R₂ = R₃ + R₄

   
   
   

   2. R₁ – R₂ = R₃ – R₄

   
   
   

   3. 	R1	=	R3
      	R2		R4

   
   
   

   4. 	R2	=	R3
      	R1		R4

      
      

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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7. In an non-inverting OP-AMP summer is shown in the figure, output voltage V₀ will be
   
   

1. 1. 		3		sin (100t)
      		2

      
      

   
   
   

   2. 3 sin (100t)

   
   
   

   3. sin (100 t)

   
   
   

   4. 2 sin (100 t)

   
   
   

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1. View Hint View Answer Discuss in Forum

   V0 = -2		1 +	2R		+ (2 + sin 100 t)		1 +	2R
   			R					R

   
   = – 6 + 6 + 3 sin 100 t = 3 sin 100 t

   Correct Option: B

   V0 = -2		1 +	2R		+ (2 + sin 100 t)		1 +	2R
   			R					R

   
   = – 6 + 6 + 3 sin 100 t = 3 sin 100 t

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8. Magnitude of the gain in the inverting op-amp amplifier circuit shown in the figure be x with switch S₁ open. When switch S₁ is closed, then magnitude of gain becomes
   
   

1. 1. 	x
      	2

      
      

   
   
   

   2. – x
      

   
   
   

   3. 2x

   
   
   

   4. – 2x

   
   
   

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1. View Hint View Answer Discuss in Forum

   	Vo	= A =	-2R	= -2 = x
   	Vi		R

   
   When switch S₁ is closed,
   

   A =	-R	= -1 =	x
   	R		2

   Correct Option: A

   	Vo	= A =	-2R	= -2 = x
   	Vi		R

   
   When switch S₁ is closed,
   

   A =	-R	= -1 =	x
   	R		2

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9. If I .C. amplifier shown in the figure has an input volt age V_i = 0.1 cos (2π × 100t) volt s, t hen waveform of the output voltage V₀ is
   
   
   

1. 1. 
      

   
   
   

   2. 
      

   
   
   

   3. 
      

   
   
   

   4. 
      

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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10. In the OP-AMP circuit shown in the given figurs V₀ is given by
    
    

1. 1. 2 V_s

   
   
   

   2. – 2 V_s

   
   
   

   3. 3 V_s

   
   
   

   4. – 3 V_s

   
   
   

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1. View Hint View Answer Discuss in Forum

   	V0	=	3R	= 3
   	Vs		R

   
   ⇒ V₀ = 3V_s

   Correct Option: C

   	V0	=	3R	= 3
   	Vs		R

   
   ⇒ V₀ = 3V_s

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