HighMarks

Errors, accuracy and precision — KCSE Physics

KCSE Physics · 113 practice questions · 9 syllabus objectives

38 easy37 medium38 hard

What You'll Learn

Key learning outcomes for this topic, aligned to the KNEC KCSE syllabus.

Apply averaging and correct technique to reduce errors in experiments

Distinguish between accuracy and precision and give examples of each in experimental measurement

Calculate absolute error, relative (fractional) error and percentage error for a given measurement

Identify sources of systematic and random errors in experiments and suggest methods to minimise them

Distinguish between systematic and random errors and give examples of each

Identify and correct for zero errors on vernier calipers and micrometer screw gauges

Read vernier caliper and micrometer screw gauge scales and record measurements correctly

Calculate percentage error in measurements of length, area and volume

Errors, accuracy and precision

Sample Questions

Try 3 questions free. Sign up to access all 113 questions with full marking schemes.

1
easySHORT ANSWER4 marks

Name two sources of systematic errors and one method to minimise each in an experiment measuring the force of gravity using a spring scale. (4 marks)

View Marking Scheme
Part (a) — 4 marks
Calibration error of the spring scale; minimise by regularly calibrating the scale before use (2 mks)
Zero error due to the scale not reading zero when unloaded; minimise by ensuring the scale is zeroed before measurements (2 mks)
2
easySHORT ANSWER3 marks

A student measures the length of a wooden plank and records it as 2.50 m. If the true length is known to be 2.45 m, calculate the absolute error, relative error, and percentage error. (3 marks)

View Marking Scheme
Part (a) — 1 mark
Absolute error = |Measured value - True value| = |2.50 m - 2.45 m| = 0.05 m (1 mk)
Part (b) — 1 mark
Relative error = Absolute error / True value = 0.05 m / 2.45 m = 0.02041 (1 mk)
Part (c) — 1 mark
Percentage error = (Relative error × 100) = 0.02041 × 100 = 2.04% (1 mk)
3
easySHORT ANSWER3 marks

Define accuracy and precision in the context of experimental measurements. Provide an example of an accurate measurement that is not precise. [3 marks]

View Marking Scheme
Part (a) — 1 mark
Accuracy: how close a measurement is to the true value (1 mk)
Part (b) — 1 mark
Precision: the degree to which repeated measurements under unchanged conditions show the same results (1 mk)
Part (c) — 1 mark
Valid example: e.g. measurements of 4.8 cm, 5.2 cm, and 5.0 cm with a true value of 5.0 cm (1 mk)
4

List two types of measurement errors and provide one example of each type. (4 marks)

+110 More Questions

Sign up free to access all 113 questions with marking schemes, track your progress, and get personalised recommendations.

Why Practise Errors, accuracy and precision?

KNEC Aligned

Questions match the KCSE syllabus objectives and exam format exactly.

Detailed Marking Schemes

Every answer shows exactly what examiners award marks for.

Track Your Mastery

See your score improve as you practise and identify remaining gaps.

Master Errors, accuracy and precision for KCSE

Sign up free to unlock all 113 questions, track your progress, and get a personalised study plan for Physics.