Physics 0625 · IGCSE · Electric circuits

Electric circuits — practice question

Fig. 8.1 presents a circuit that is intended to turn on a night light when the surroundings are dark.

(a(i))[1]

On Fig. 8.1, add the circuit symbol for a voltmeter that measures the potential difference (p.d.) across the light-dependent resistor (LDR).

(a(ii).1)[1]

State how this change affects the resistance of the LDR.

(a(ii).2)[2]

State and explain how this change affects the p.d. across the light-emitting diode (LED).

(b)[3]

Calculate the resistance of lamp A.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Voltmeter symbol correctly placed across the LDR” …