Physics 9702 · AS & A Level · Errors and uncertainties

Errors and uncertainties — practice question

An analogue voltmeter is used to measure a steady potential difference across a resistor.
(a(i))[1]

For these measurements, give one example of a systematic error.

(a(ii))[1]

For these measurements, give one example of a random error.

(b(i))[2]

The potential difference across a resistor is recorded as $5.0\,\text{V} \pm 0.1\,\text{V}$. The resistor is labelled as having a resistance of $125\,\Omega \pm 3\%$. Calculate the power dissipated by the resistor.

(b(ii))[2]

Calculate the percentage uncertainty in the calculated power.

(b(iii))[2]

Determine the value of the power, with its absolute uncertainty, to an appropriate number of significant figures.

Worked solution & mark scheme

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