Physics 5054 · O Level · Electric circuits

Electric circuits — practice question

A light-dependent resistor (LDR) is used to detect how bright the light is in a room.
(a(i))[1]

Complete Fig. 6.1 by sketching the circuit symbol for an LDR between points P and Q.

(a(ii))[2]

Explain how the voltmeter reading changes when the amount of light falling on the LDR rises.

(b(i))[2]

Show that the current through the $5.0\,\Omega$ resistor is $1.9\,\text{A}$.

(b(ii))[2]

Calculate the potential difference (p.d.) across points X and Y.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: the correct LDR symbol with 2 or 3 arrows

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