Concept of virtual ground:
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--This is known as inverting configuration of op-amp .(with negative feedback)
Input impedance of op-amp is very high
--Hence op-amp never draws any current at
it’s input, hence input current is always zero.
--Iin =0 amperes
--For current to be zero the voltage Va must be zero,thus even though the input is applied , the inverting terminal behaves as ground terminal at node ‘a’.
--This concept is known as virtual ground concept.
A--Gain of op-amp with negative feedback in inverting configuration
Q 1) Let us find the gain of op-amp with negative feedback in
The input is applied to negative terminal of op-amp.
--R1 is applied input resistance.
--Rf is feedback resistance.
Ans-->
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Q 2)Find the gain and output voltage of op-amp .
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| INVERTING &NON INVERTING FORMULAS WITH DIGRAM |
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