Physics (AS & A Level) · Oct / Nov 2018 · Paper 11 · Question 38

The diagram shows a battery of electromotive force (e.m.f.) 6 V, connected in series with a resistor and a uniform resistance wire RQ of length 60 cm. The resistance of RQ is equal to the resistance of the resistor. [diagram: battery 6 V connected in series with a resistor and uniform resistance wire RQ; terminal X connected to fixed point R, terminal Y connected to point P on the wire; L is the distance between R and P] Terminal X is connected to fixed point R. Terminal Y is connected to point P, a connection that may be made at any position along the wire. L is the distance between R and P. Which graph shows the variation with L of the potential difference (p.d.) V across XY?

1. AGraph A: V/V against L/cm, straight line from origin (0,0) rising to 6 at L = 60 cm
2. BGraph B: V/V against L/cm, straight line from origin (0,0) rising to a value below 6 at L = 60 cm
3. CGraph C: V/V against L/cm, straight line from 6 at L = 0 falling to 0 at L = 60 cm
4. DGraph D: V/V against L/cm, straight line from a value below 6 at L = 0 falling to 0 at L = 60 cm

As printed in the paper