CEnT-S physics
Physics closes the test: five questions in ten minutes, worth five of the fifty-five marks. It is the shortest section and the easiest to underestimate, because the syllabus covers five separate areas and the test draws roughly one question from each.
The five areas
Measurement and vectors
Units and their prefixes, and combining vectors. Two perpendicular forces combine through the Pythagorean theorem, not by addition: three newtons and four newtons at right angles give five, never seven.
Kinematics
Uniform motion and uniform acceleration, and the three equations that follow from them. Starting from rest, distance is ½at², and the half comes from the speed rising steadily rather than being constant.
Dynamics, work and energy
Newton's laws, work, kinetic and potential energy, and power. Work is measured in joules and power in watts, and a question that gives you a time is usually asking for the second.
Fluids and thermodynamics
Density, pressure, pressure in a fluid column, and heat. During a change of state the temperature holds steady while energy continues to be absorbed, because the energy goes into breaking bonds rather than into molecular motion.
Electromagnetism
Charge, current, potential difference and resistance, Ohm's law and simple circuits. Resistors in series add; in parallel the reciprocals add.
Ten minutes, five questions
Two minutes each, with no calculator and no formula sheet, means these are single-step applications rather than multi-stage problems. A question that needed three substitutions could not be finished, so the test does not set one.
Take g as 10 m s⁻² unless a question says otherwise. Numbers are chosen so the arithmetic is clean: masses and distances in whole units, square roots of perfect squares.
Because the section is short, one careless answer costs a fifth of it. With a quarter-mark penalty on top, physics is the section where the gap between a strong and a weak performance is widest per question. How the penalty is calculated →
The formulas are not supplied
This is the section where memorisation matters most, because almost every question is a formula applied once. The kinematic equations, F = ma, work and power, density and pressure, Q = mcΔT and Q = mL, and Ohm's law all have to be brought with you. Full formula list →
Where marks are lost
Dropping a factor. Leaving the half out of s = ½at² doubles the answer, and the doubled value is among the options.
Stopping one step early. Work done against gravity is mgh, and power is that divided by the time. A question that gives a duration wants the second number, and the first is offered as a distractor.
Inverting a relationship. Ohm's law multiplies resistance by current; dividing them gives a quantity that is not a potential difference at all, which a check on the units catches in a few seconds.
Assuming heating raises temperature. During melting or boiling it does not, and that is the whole point of latent heat.
Practise the section
Five original physics questions
Under the real ten-minute limit, with the constants stated and every answer explained.
Start practice →