Electronic Devices - Op-Amp Applications - Discussion

Discussion :: Op-Amp Applications - General Questions (Q.No.6)

6. 

Calculate the output voltage if V1 = V2 = 0.15 V.

[A]. 0 V
[B]. 4.65 V
[C]. 6.45 V
[D]. –6.45 V

Answer: Option D

Explanation:

No answer description available for this question.

Chandan Natkar said: (Sep 25, 2011)  
It is inveting summer

Vo=(-Rf/R1)V1+(-Rf/R2)V2
=(-330/33)0.15+(-330/10)0.15
=-1.5-4.95
=-6.45

Mallik said: (Mar 26, 2012)  
Ok just. If you find it difficult to remember formula .. here is the way...

rules
1)both the terminals of Op-amp are always at same voltage levels,
2)current entering into Op-amp is always '0'.

now write equation
[(V1-Vb)/33k]+[(V2-Vb)/10k]+[(Vo-vb)/330k] = 0;
from KCL

(10*V1)+(33*V2)+Vo=0
=> Vo= -(43*0.15)
V0= -6.45

Rajasekhar said: (Jan 26, 2014)  
What is vb? and how can you solve the problem?

Subrat said: (Jun 12, 2014)  
Vb is the voltage at non inverting terminal (-ve).

Madhu Adkar said: (Oct 6, 2015)  
Since non inverting terminal is grounded Vb=0V.

Mulata said: (Apr 3, 2016)  
Yes, but what about +9 V and -9 V?

Vijay said: (Jul 19, 2016)  
That is the saturation voltage.

Amit said: (Feb 22, 2018)  
Vout=. --- {(v1/r1+v2/r2)} / (1/rf).
Gives -6.45 volt.

Above formula is for inverting op amp.

Shudi said: (Jan 18, 2022)  
What if v1 and v2 are in AC? Please explain.

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