Physics (AS & A Level) · May / June 2020 · Paper 13 · Question 37

A fixed resistor and a variable resistor are connected in series with a cell that has an internal resistance, as shown. The graph shows the variation of a quantity X with the resistance R of the variable resistor as R is increased from zero to its maximum value. What could X represent?

1. Athe current in the circuit
2. Bthe electromotive force of the cell
3. Cthe potential difference across the internal resistance
4. Dthe terminal potential difference across the cell

As printed in the paper