In the circuit shown below, the output at B is

Question

Question

This question was previously asked in

IPRC (ISRO) Technician B (Electronic Mechanic): Previous Year Paper (Held on 10 Dec 2016)

Answer 1

Concept:

F3 U.B Madhu 29.01.20 D 1

For an op-amp with feedback and input resistances as shown, the gain when input is at the inverting terminal is given as;

\(\frac{{{V_o}}}{{{V_i}}} = - \frac{{{R_f}}}{{{R_1}}}\)

Since the gain of the above configuration is always negative, it is known as the inverting configuration.

Analysis:

Now, if R_f = R₁, then the OP-AMP output will be negative to that of OP-AMP input.

Option 1 is the correct choice.