Paper 3 at a glance
- Paper 3 carries 15 marks
Experiment: Determining the specific heat capacity of aluminium
To determine the specific heat capacity of aluminium by supplying a measured amount of electrical energy and measuring the temperature rise.
- Manipulated: Heating time, t
- Responding: Temperature of the block, θ
- Constant: Mass of the aluminium block and the power of the heater
- Graph: Plot temperature θ (y-axis) against time t (x-axis). The straight portion has a gradient equal to the rate of temperature rise, P / (mc).
- Analysis: The electrical energy supplied equals the heat gained: VIt = mcΔθ. So c = VIt / (mΔθ). Using the graph, c = P / (m × gradient), where P = VI.
Experiment: Determining the specific latent heat of fusion of ice
To determine the specific latent heat of fusion of ice by melting it with a measured amount of electrical energy, using a control to correct for the surroundings.
- Manipulated: Whether the heater is switched on (experiment) or off (control)
- Responding: Mass of ice melted, m
- Constant: Heating time and the power of the heater
- Graph: A graph is not required. The control funnel provides the correction for ice melted by heat from the surroundings during the same time.
- Analysis: The electrical energy supplied melts the corrected mass of ice: VIt = mL, where m is the corrected mass. So the specific latent heat of fusion L = VIt / m.
Experiment: Pressure and volume of a fixed mass of gas at constant temperature (Boyle's law)
To investigate the relationship between the pressure and the volume of a fixed mass of gas kept at constant temperature.
- Manipulated: Pressure of the trapped gas, P
- Responding: Volume of the trapped gas, V
- Constant: Temperature and the mass of the trapped gas
- Graph: Plot P (y-axis) against 1/V (x-axis). A straight line through the origin shows P is inversely proportional to V.
- Analysis: Because P is inversely proportional to V at constant temperature, PV = constant. The straight-line graph of P against 1/V confirms Boyle's law.
Experiment: Volume and temperature of a fixed mass of gas at constant pressure (Charles's law)
To investigate the relationship between the volume and the temperature of a fixed mass of gas kept at constant pressure.
- Manipulated: Temperature of the gas, θ
- Responding: Length of the trapped air column (proportional to volume), L
- Constant: Pressure and the mass of the trapped gas
- Graph: Plot L (volume, y-axis) against temperature θ in °C (x-axis). The straight line, when extended back to L = 0, cuts the temperature axis near −273 °C (absolute zero).
- Analysis: At constant pressure the volume is directly proportional to the absolute (kelvin) temperature, so V / T = constant. Extrapolating the line to zero volume gives absolute zero at about −273 °C.
Experiment: Pressure and temperature of a fixed mass of gas at constant volume (pressure law)
To investigate the relationship between the pressure and the temperature of a fixed mass of gas kept at constant volume.
- Manipulated: Temperature of the gas, θ
- Responding: Pressure of the gas, P
- Constant: Volume and the mass of the trapped gas
- Graph: Plot P (y-axis) against temperature θ in °C (x-axis). The straight line, extended back to P = 0, cuts the temperature axis near −273 °C (absolute zero).
- Analysis: At constant volume the pressure is directly proportional to the absolute (kelvin) temperature, so P / T = constant. Extrapolating the line to zero pressure gives absolute zero at about −273 °C.
Paper 3 skill checklist
- Table: quantities with units in the headings, consistent decimal places, derived column calculated correctly.
- Graph: axes labelled with unit, scale using more than half the grid, points plotted with a sharp pencil, best-fit line.
- Gradient: a large triangle on the line, coordinates shown, unit of the gradient stated.
- Relationship: "y increases linearly with x" or "y is directly proportional to x" only if the line passes through the origin.
- Precaution: one that improves accuracy, stated with its reason.
More on graph skills
Exam tip
Units on every calculation line; no formula is provided in the SPM Physics papers.
More Heat resources
- Chapter overview: Heat
- Revision Notes
- Common Mistakes
- Practice Questions
- Paper 2 Answering Guide
- Key Terms
- Calculation practice sets
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