Physics (AS & A Level) · Oct / Nov 2017 · Paper 13 · Question 35

An ideal diode has zero resistance when forward biased and infinite resistance when reverse biased. The diode is connected in series with a 2 Ω resistor across the terminals of a source having electromotive force (e.m.f.) 3 V and internal resistance 1 Ω, as shown. A high-resistance voltmeter is connected across the diode and resistor. Which row gives the readings of the voltmeter for the two ways of connecting the diode?

1. Aforward biased: 1 V; reverse biased: 3 V
2. Bforward biased: 2 V; reverse biased: 0 V
3. Cforward biased: 2 V; reverse biased: 3 V
4. Dforward biased: 3 V; reverse biased: 0 V

As printed in the paper