Physics (AS & A Level) · May / June 2022 · Paper 11 · Question 35

A cell has internal resistance r and electromotive force (e.m.f.) E. The cell is connected in series with an ammeter and a variable resistor of resistance R. When R is 10 Ω the ammeter reads 0.3 A. When R is 5 Ω the ammeter reads 0.4 A. What is the value of E?

1. A0.5 V
2. B2 V
3. C3 V
4. D6 V

As printed in the paper