CAPE Physics Unit 2 · 2007 · Paper 1 · Question Q22

The figure shows an op-amp used as a comparator. The open loop voltage gain of the op-amp is 3 \times 10^5 and the voltage of the power supply is \pm 6\text{ V}. The MINIMUM input voltage (V_i) which will cause saturation is

1. (A)\pm 20\,\mu\text{V}
2. (B)\pm 30\,\mu\text{V}
3. (C)\pm 40\,\mu\text{V}
4. (D)\pm 180\,\mu\text{V}

This question uses a figure or table from the paper — you'll see it when you practise.