Paper 2 at a glance
- Section C: 1 item worth 20 marks
"Define" items from this chapter
One precise sentence each; the unit is part of the definition where there is one.
- Sensitivity, The ability of an instrument to detect and respond to a small change in the quantity being measured.
- Physical quantity, A quantity that can be measured, consisting of a numerical value and a unit.
- Base quantity, A physical quantity that cannot be defined in terms of other physical quantities; the five in physics are length, mass, time, electric current and temperature.
- Derived quantity, A physical quantity obtained by combining base quantities through multiplication or division, such as speed or density.
- Scalar quantity, A physical quantity that has magnitude only, with no direction, such as distance, speed and mass.
- Vector quantity, A physical quantity that has both magnitude and direction, such as displacement, velocity and force.
"Explain" items from this chapter
Give the physics reason, not a description. Model answers in one breath:
- Why significant figures matter, Significant figures state how precisely a quantity was measured. Writing more digits than your instrument can resolve claims a precision you do not actually have.
- Scalars and vectors in everyday terms, A scalar has size only, while a vector has both size and direction. Confusing the two changes the physics, because directions can cancel out but sizes cannot.
- Why a vernier caliper reads finer than a ruler, An instrument can only be trusted down to its smallest division. A vernier caliper and micrometer have finer scales than a metre rule, so they resolve smaller lengths.
Diagram and description items
This chapter carries no formula, so Paper 2 marks come from labelled diagrams, descriptions of procedures and precise definitions. Practise drawing each diagram from memory with every label.
- SI unit, The internationally agreed system of units for physical quantities, based on the seven SI base units such as the metre, kilogram and second.
- Prefix, A word or symbol placed before a unit to indicate a multiple or fraction of it, such as kilo- (10³) or milli- (10⁻³).
- Significant figures, The digits in a measurement that carry meaningful information about its precision.
- Measurement error, The difference between a measured value and the true value of a quantity.
- Precision, The ability of an instrument to give consistent, closely grouped readings when a measurement is repeated.
- Accuracy, How close a measured value is to the true or accepted value of a quantity.
Other command words
- Sketch, axes labelled with units, the shape that matters (curve vs straight line, intercept, origin), no plotted numbers needed.
- Compare, same feature, both cases, one line each, then the physics that links them.
Where the marks are in this chapter
The 2 content standards of Measurement can each be asked as a definition, an explanation, a calculation or a diagram. We do not predict which will appear, prepare all of them.
A three-step answer routine
- Decide the answer type first: definition, reason, number or drawing.
- For numbers, write the rearranged formula on its own line before substituting.
- Check the magnitude is sensible for the situation before moving on.
Exam tip
Units on every calculation line; no formula is provided in the SPM Physics papers.
More Measurement resources
Source: DSKP KSSM Physics Form 4 and 5 (Versi English), Sijil Pelajaran Malaysia: Format Pentaksiran mulai 2021, Fizik (4531) (Bahagian Pembangunan Kurikulum (BPK), KPM)
Written by the spmphysics.com.my editorial team.· Updated 5 Sept 2026