Edexcel A-Level Physics Percentage Uncertainty

Practise Edexcel A-Level Physics percentage uncertainty using half-ranges, mean values, resolution comparisons and uncertainty propagation.

Exam points

calculate mean values and absolute uncertainty from half the range of repeated readings
calculate percentage uncertainty from absolute uncertainty divided by measured value
compare measurement methods by using larger measured quantities to reduce percentage uncertainty

[Maximum number: 2]

A strain gauge is a sensor made from metal foil fixed to a plastic sheet, as shown.

Figure for Question 3.5.9 - Percentage uncertainty question 1 — Edexcel A-Level Physics AS

Bending the plastic sheet changes the dimensions of the metal foil.
This changes the resistance of the metal foil.
A student connected the strain gauge into the circuit shown below.

The student switched on the power supply and the voltmeter displayed the following reading: 16.2 mV.

Determine the percentage uncertainty in this reading.

Percentage uncertainty =

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3.5.9 - Percentage uncertainty question 1