IGCSE Physics (0625)

Reading an analogue meter (ammeter, voltmeter)

What this topic tests, the mistakes that cost marks, and one exam-style question worked through step by step.

Key ideas and common mistakes

Reading an analogue scale requires identifying the value at which the needle points, ensuring the correct interpretation of scale divisions and not miscounting the intervals between labeled values.
Reading an analogue scale requires identifying the value at the needle's position and including the correct number of decimal places based on the scale's labeling.
Common mistake: Students often omit the trailing zero (e.g., write 3 instead of 3.0) when the scale is marked in whole numbers but the context requires a decimal.
Reading an analogue scale requires identifying the value at the needle's position, matching the scale's units and subdivisions, rather than estimating or rounding to the nearest major division.
To read an analogue scale, calculate the value of each small division by dividing the interval between numbered marks by the number of divisions, then add the correct number of divisions to the nearest numbered mark.
Common mistake: A common mistake is to miscount divisions or miscalculate their value.
To read an analog scale correctly, calculate the value of each small division and add the appropriate number to the nearest labelled mark, recording the answer to the same decimal place as the smallest division.
Common mistake: Students often miscount divisions or use the wrong precision.
Reading analog meter scales requires counting the value per small division and adding to the nearest labelled value.
Common mistake: Students often miscount divisions or misidentify the unit, confusing volts with amperes or vice versa.

Worked example

State the reading shown on the ammeter.

Try it first, then show the working

0.45 A

The needle points to 0.45 on the 0-1.0 A scale, so the ammeter reads 0.45 A.

Answer: 0.45 A

Try one yourself

The diagram shows the dial of an ammeter used in an experiment. Record the ammeter reading shown.Answer it and get it marked → The diagram shows the dial of a voltmeter. Record the voltmeter reading shown.Answer it and get it marked → State the reading shown on the voltmeter.Answer it and get it marked →

14 exam-style questions on Reading an analogue meter (ammeter, voltmeter), each marked to the scheme.

Reading an analogue meter (ammeter, voltmeter)

Key ideas and common mistakes

Worked example

Try one yourself

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