Physics (AS & A Level) · Feb / March 2021 · Paper 12 · Question 34

A fixed resistor and a diode are connected in series to a battery of electromotive force (e.m.f.) 6.0 V and negligible internal resistance. The graph shows the variation with potential difference (p.d.) V of the current I for the diode. The current in the diode is 40 mA. What is the resistance of the fixed resistor?

1. A30 Ω
2. B120 Ω
3. C150 Ω
4. D180 Ω

As printed in the paper