Free·GCSE Physics
Free GCSE Physics Questions and Answers
12 questions, one from each topic, with the answer that takes every mark and what it is worth. Nothing to sign up to and nothing to download — they are on this page.
Energy and power, Forces, Motion, Waves and the electromagnetic spectrum, Electricity, Magnetism and electromagnetism, Particle model of matter, Atomic structure, radioactivity and space and Apparatus and working scientifically
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Explain why the total energy of a closed system does not change when energy is transferred within it.
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The full-mark answer · 3 marks
A closed system is one in which no energy enters or leaves. Energy inside it can be transferred from one store to another, but it cannot be created or destroyed, so any decrease in one store is matched by an equal increase in another. The total is unchanged, although the energy is stored differently at the end.
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Suggest two ways of reducing the unwanted energy transfer from a house, and explain how each works.
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The full-mark answer · 4 marks
Loft insulation traps air in a material of low thermal conductivity, so energy is conducted out through the roof more slowly. Double glazing places a gap of air, or a vacuum, between two panes, lowering the conductivity of the window and so the rate of energy transfer through it. Both reduce the rate of transfer rather than preventing it.
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Describe the difference between mass and weight.
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The full-mark answer · 3 marks
Mass is the quantity of matter in an object, measured in kilograms, and it does not change with location. Weight is the force acting on that mass because of a gravitational field, measured in newtons, and it depends on the gravitational field strength — so the same object weighs less on the Moon while its mass is unchanged.
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Calculate the weight of a 7.5 kg object on Earth, where g is 9.8 N/kg.
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The full-mark answer · 2 marks
W = mg = 7.5 × 9.8 = 73.5 N.
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State what is meant by a vector quantity.
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The full-mark answer · 2 marks
A vector quantity has both a magnitude and a direction — for example velocity, force or displacement. A scalar quantity has magnitude only.
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Explain the difference between speed and velocity, using an example.
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The full-mark answer · 3 marks
Speed is a scalar quantity: it states only how fast something is moving. Velocity is a vector: it states the speed together with the direction of motion. Because velocity includes direction, it changes whenever the direction changes even if the speed is constant — a car travelling round a roundabout at a steady 20 mph has a constant speed but a continuously changing velocity.
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Name the quantity measured from the middle of a wave to a crest.
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The full-mark answer · 1 mark
The amplitude.
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State what an electric current is, in terms of charge.
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The full-mark answer · 2 marks
An electric current is the rate of flow of electric charge — the charge passing a point in the circuit each second. It is measured in amperes, where one ampere is one coulomb per second.
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State what happens when two north poles are brought together.
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The full-mark answer · 1 mark
They repel each other.
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Calculate the density of a 240 g block of volume 300 cm³.
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The full-mark answer · 3 marks
ρ = m / V = 240 / 300 = 0.80 g/cm³. In SI units this is 800 kg/m³, since 1 g/cm³ is 1000 kg/m³.
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Name the particle in the nucleus that has no charge.
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The full-mark answer · 1 mark
The neutron.
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Describe how you would measure the density of a small irregular solid.
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The full-mark answer · 4 marks
Find the mass of the dry object on a balance. Part-fill a measuring cylinder with water and record the level, reading the bottom of the meniscus at eye level. Lower the object in on a thread until it is completely submerged and record the new level. The difference between the two readings is the volume of the object. Divide the mass by that volume to obtain the density.
What the book adds
These are the answers that score everything. GCSE Physics Questions & Answers is the other half: the same questions answered weakly, middlingly and strongly, the mark each version scores, what separates them, and the mark scheme behind it — a hundred questions across every topic, written for the teacher marking them rather than the pupil sitting them.