Physics 9702 · AS & A Level · Errors and uncertainties
Errors and uncertainties — practice question
A three-digit digital voltmeter is used to measure the potential difference across a resistor. The meter’s manufacturer states that its accuracy is $1\%$ and $1$ digit. The voltmeter shows $2.05\,\text{V}$.
(a(i))[1]
For this reading, Calculate the change in the voltmeter reading that corresponds to $1\%$, rounded to the nearest digit.
(a(ii))[1]
For this reading, Calculate the largest possible value of the potential difference across the resistor.
(b)[2]
The reading on the voltmeter is highly precise. State and explain why it may still be inaccurate.
Worked solution & mark scheme
This 4-mark question has a full step-by-step worked solution and mark scheme. One marking point: “1% of $\pm 2.05$ gives $\pm 0.02$” …