Physics 5054 · O Level · Resistance

Resistance — practice question

A student explores how the resistance of a filament lamp varies as the potential difference $V$ across it is changed. He uses the circuit shown in Fig. 3.1.
(a)[2]

On Fig. 3.1, draw the symbol for an ammeter and the symbol for a voltmeter in the positions that are correct for this investigation.

(b(i))[1]

Suggest how he alters his circuit to do this.

(b(ii))[1]

Fig. 3.2 gives the current $I$ readings on the ammeter for each voltage. Record the value of $I$ shown on the meter for each voltage.

(b(iii))[1]

Use the equation $R = \frac{V}{I}$ to calculate the resistance $R$ of the lamp at $4.0\,\text{V}$ and at $8.0\,\text{V}$. Include the unit in your answers.

(c)[2]

State two physical changes observed in the lamp as the potential difference $V$ increases.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: Ammeter connected in series

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