Topic: Analog Circuits
An op-amp has an offset voltage of 1 mV and is ideal in all other respects. If this op-amp is used in the circuit shown in figure, the output voltage will be
- A. 1 mV
- B. 1V
- C. $\pm 1~V$
- D. OV
Answer: C. $\pm 1~V$
Explanation: $V_0 = (1 + \frac{R_f}{R_1})V_{i0}$\nWhere $V_{i0} =$ input offset voltage\n$V_0 = (1 + \frac{1 \times 10^6}{1 \times 10^3}) \times 1 \times 10^{-3} = 1001 \times 1 \times 10^{-3} = 1.001~V \simeq 1~V$\nNature can not be predicted\nSo $V_0 = \pm 1~V$