281. Find Av =	v0
     	vi

     
     
     

1. 1. 5

   
   
   

   2. – 5

   
   
   

   3. 6

   
   
   

   4. – 6

   
   
   

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1. View Hint View Answer Discuss in Forum

   V_A = V_i (due to virtual ground) KCL at node A.
   

   	VA – VB	+	VA – 0	= 0
   	R		R

   
   or 2 V_A = V_B
   KCL at node B.
   

   	VB – VA	+	VB	+	VB – V0	= 0
   	R		R		R

   
   

   or	2VA – VA	+	2VA	+	2VA – V0	= 0 (VB = 2 VA)
   	R		R		R

   
   

   or	Vi	+	2Vi	+	2Vi	=	V0	(Vi = VA)
   	R		R		R		R

   
   or 5 V_i = V₀
   

   or	V0	= 5
   	Vi

   
   

   Correct Option: A

   V_A = V_i (due to virtual ground) KCL at node A.
   

   	VA – VB	+	VA – 0	= 0
   	R		R

   
   or 2 V_A = V_B
   KCL at node B.
   

   	VB – VA	+	VB	+	VB – V0	= 0
   	R		R		R

   
   

   or	2VA – VA	+	2VA	+	2VA – V0	= 0 (VB = 2 VA)
   	R		R		R

   
   

   or	Vi	+	2Vi	+	2Vi	=	V0	(Vi = VA)
   	R		R		R		R

   
   or 5 V_i = V₀
   

   or	V0	= 5
   	Vi

   
   

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282. In a time base generator a constant current source (I) is used to drive a capacitance (C). The output voltage across the capacitance as a function of time (t) is given by:

1. 1. I	t
      C

   
   
   

   2. C	t
      I

   
   
   

   3. ICt

   
   
   

   4. t

      IC

   
   
   

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1. View Hint View Answer Discuss in Forum

   q = C V
   It = C V
   

   or V =	It
   	C

   Correct Option: A

   q = C V
   It = C V
   

   or V =	It
   	C

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283. A differentiator is rarely used in analog computers as it:

1. 1. reduces the gain

   
   
   

   2. decreases the output of the amplifier

   
   
   

   3. amplifies noise, drift and other unwanted disturbances

   
   
   

   4. may cause oscillation

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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284. The circuit shown below is best described as:
     
     
     

1. 1. voltage follower

   
   
   

   2. monostable multivibrator

   
   
   

   3. Schmitt trigger

   
   
   

   4. high input impedance amplifier

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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285. In the circuit, shown below I₀ is given by:
     
     
     

1. 1. VS ×	RL
      	RS(RL + RS)

   
   
   

   2. VS

      RS

   
   
   

   3. VS

      RL

   
   
   

   4. VS ·		1	+	1
      		RL		RS

   
   
   

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1. View Hint View Answer Discuss in Forum

   Due to virtual ground voltage at terminal is V_s. Now, KCL at A
   

   Io –	Vs	= 0
   	Rs

   
   

   or Io =	Vs
   	Rs

   
   

   Correct Option: B

   Due to virtual ground voltage at terminal is V_s. Now, KCL at A
   

   Io –	Vs	= 0
   	Rs

   
   

   or Io =	Vs
   	Rs

   
   

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