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GCSE Physics measurement and data practice

Read an oscilloscope trace and calculate the mean of repeated timings.

Practise

Frequency

Find the frequency in Hz of trace A. Give your answer to 3 significant figures.

Ideal sinusoidal voltage traces; one large square is one division. A is solid and B, when present, is dashed. Both channels have the same sensitivity and time-base.

Trace A has amplitude 1.5 divisions and period 5 divisions. Vertical sensitivity 1 V/div; time-base 0.1 ms/div.A solid1 V/div · 0.1 ms/div0 V
One large square is one division; the middle horizontal line is 0 V.
Diagram text alternative

Trace A has amplitude 1.5 divisions and period 5 divisions. Vertical sensitivity 1 V/div; time-base 0.1 ms/div.

Larger diagram
Trace A has amplitude 1.5 divisions and period 5 divisions. Vertical sensitivity 1 V/div; time-base 0.1 ms/div.A solid1 V/div · 0.1 ms/div0 V

Treat the given values as exact unless an uncertainty is stated.

Use decimals or e notation, e.g. 4.2e-3. Enter the unit separately.

Hint

Measure one complete cycle, multiply by ms/div, then convert milliseconds to seconds. For frequency, use f = 1/T.

Worked solution
  1. T = 5 × 0.1 = 0.5 ms = 0.0005 s.
  2. f = 1/T.
  3. Answer: 2.00 × 103 Hz (3 significant figures).
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Question type: Mixed practice
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Foundation and Higher: this set covers content common to both tiers. Some calculations need several steps.

Scales and repeated readings

On the ideal trace, count divisions and multiply by the scale setting. Voltage amplitude is measured from the centre line to a peak; period is the interval between equivalent points in adjacent cycles. Add repeat timings and divide by their count to find the mean. A mean can reduce the effect of random variation but cannot correct a constant timing offset.

GCSE scope

AQA 8463: AT 1, 4; required practical 8; MS 2b; OCR Gateway J249: P5.1a; P9; 5g M2b. Tasks cover the selected skills listed above.

AQA specification · OCR Gateway specification

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