O Level / IGCSE Physics MCQs with answers
Practise O Level / IGCSE Physics (5054 / 0625) with 361 exam-style MCQs, each with the answer and a short explanation. Every test is marked the moment you finish and shows your score chapter by chapter, so you know what to revise next. It is free and needs no sign-up.
361 questions · 6 chapters · 14 Cambridge past papers · 5 mock exams
What each chapter covers 6 chapters
The questions follow the syllabus chapter by chapter. You can test the whole subject or one chapter at a time.
- Motion, forces and energy 118 questionsPhysical quantities and measurement techniques, Motion, Mass and weight, Density, Forces, Momentum, Energy, work and power, Pressure
- Thermal physics 42 questionsKinetic particle model of matter, Thermal properties and temperature, Transfer of thermal energy
- Waves 58 questionsGeneral properties of waves, Light, Electromagnetic spectrum, Sound
- Electricity and magnetism 86 questionsSimple magnetism and magnetic fields, Electrical quantities, Electric circuits, Practical electricity, Electromagnetic effects, Uses of an oscilloscope
- Nuclear physics 29 questionsThe nuclear model of the atom, Radioactivity
- Space physics 28 questionsEarth and the Solar System, Stars and the Universe
Sample O Level / IGCSE Physics MCQs with answers 12 questions
12 questions from the test, one or two from each chapter. Try each one, then open the answer.
1. Why do modern cars have crumple zones at the front?
- A
to make the car lighter
- B
to increase the time of the collision and so reduce the force
- C
to increase the momentum of the car
- D
to stop the car faster
Show answer
Answer: B. Force = change in momentum ÷ time. The momentum change is fixed, so a longer collision time gives a smaller force on the passengers.
2. A gas is kept at constant temperature while its volume is halved. What happens to its pressure, and why?
- A
it halves, because the particles slow down
- B
it doubles, because the particles hit the walls more often
- C
it stays the same, because temperature is constant
- D
it doubles, because the particles move faster
Show answer
Answer: B. At constant temperature the particles keep the same speed, but in half the volume they strike the walls twice as often, so pressure doubles (pV = constant).
3. Which radiation harms the body mainly by heating soft tissue, rather than by ionising it?
- A
gamma rays
- B
microwaves
- C
ultraviolet
- D
X-rays
Show answer
Answer: B. Microwaves are absorbed by the water in tissue and heat it, which can cause burns. Ultraviolet, X-rays and gamma rays are ionising and can cause cell mutation and cancer.
4. Resistors of 4.0 Ω and 12 Ω are connected in parallel. The current in the 4.0 Ω resistor is 0.90 A. What is the current in the 12 Ω resistor?
- A
0.30 A
- B
0.90 A
- C
1.2 A
- D
2.7 A
Show answer
Answer: A. Parallel resistors have the same p.d.: V = 0.90 × 4.0 = 3.6 V. Current in 12 Ω = 3.6 ÷ 12 = 0.30 A. The larger resistor takes the smaller current; 2.7 A has the ratio upside down.
5. A radioactive tracer is injected into a patient to check kidney function. Which isotope properties are most suitable?
- A
alpha emitter, long half-life
- B
gamma emitter, short half-life
- C
beta emitter, very long half-life
- D
alpha emitter, short half-life
Show answer
Answer: B. Gamma passes out of the body to be detected and is weakly ionising; a short half-life limits the dose after the test. Alpha inside the body would cause severe damage.
6. What powers a stable star like the Sun?
- A
burning of hydrogen gas in oxygen
- B
nuclear fission of uranium
- C
nuclear fusion of hydrogen into helium
- D
gravitational collapse alone
Show answer
Answer: C. In the core, hydrogen nuclei fuse into helium, releasing energy. The outward pressure from this balances the inward pull of gravity, keeping the star stable.
7. A student times 20 complete swings of a pendulum and gets 30.0 s. What is the period of the pendulum?
- A
0.67 s
- B
1.5 s
- C
15 s
- D
600 s
Show answer
Answer: B. Period = time for one swing = 30.0 ÷ 20 = 1.5 s. Timing many swings reduces the effect of reaction time.
8. Why are metals good conductors of thermal energy?
- A
their particles are far apart
- B
they contain free electrons that carry energy quickly through the metal
- C
they have a low density
- D
they do not expand when heated
Show answer
Answer: B. All solids conduct by lattice vibrations, but metals also have free electrons that move through the metal, transferring energy much faster.
9. A microwave oven uses waves of frequency 2.4 GHz. What is their wavelength? (speed of electromagnetic waves = 3.0 × 108 m/s)
- A
0.0125 m
- B
0.125 m
- C
8.0 m
- D
125 m
Show answer
Answer: B. 2.4 GHz = 2.4 × 109 Hz. λ = v ÷ f = 3.0 × 108 ÷ 2.4 × 109 = 0.125 m. Treating GHz as MHz (106) gives 125 m; dividing f by v gives 8.0.
10. An oscilloscope trace shows exactly 2 complete cycles across 10 horizontal divisions. The timebase is set to 0.1 ms per division. What is the frequency of the signal?
- A
200 Hz
- B
1000 Hz
- C
2000 Hz
- D
5000 Hz
Show answer
Answer: C. The 10 divisions last 10 × 0.1 ms = 1.0 ms and hold 2 cycles, so the period is 0.5 ms = 0.0005 s. Frequency = 1 ÷ 0.0005 = 2000 Hz. Taking 1.0 ms as one period gives 1000 Hz.
11. Which is the largest source of background radiation for most people?
- A
nuclear power stations
- B
radon gas from rocks and soil
- C
medical X-rays
- D
cosmic rays only
Show answer
Answer: B. Radon gas from the ground is the biggest contributor for most people, followed by rocks and buildings, food and drink, cosmic rays and medical uses.
12. Planet P orbits the Sun further out than planet Q. Which is correct for planet P?
- A
a longer orbital period and a lower orbital speed
- B
a longer orbital period and a higher orbital speed
- C
a shorter orbital period and a lower orbital speed
- D
the same orbital speed as Q, as both orbit the Sun
Show answer
Answer: A. The Sun's gravitational field is weaker further out, so planets there move more slowly. They also have a longer path to travel, so their orbital period is longer.
Try 349 more questions
Ways to practise 7 ways
- Quick check. 10 questions drawn fresh each time, about 10 minutes.
- By chapter. 10 questions from one chapter, for the topic you are revising now.
- Full paper. A full-length timed paper across the whole syllabus.
- Past papers. 14 Cambridge multiple-choice papers, answered on screen and marked for you.
- Mock exams. 5 full papers of our own questions in the style of the real paper.
- Practice mode. See the right answer and an explanation after every question, with no clock.
- Exam mode. Timed like the real paper, with no going back.
When you get a question wrong, a short note called "The idea behind this" explains the topic it belongs to, with the rules to remember and a worked example.
Common questions
Is this O Level / IGCSE Physics test free?
Yes. Every test and every explanation is free, and you do not need an account. If you sign in, your results are kept across your devices.
Are these past paper questions?
The 361 MCQs are our own, written to the syllabus in the style of the exam. The 14 Cambridge past papers are listed separately inside the test.
How is the test marked?
Instantly. You get your score, the right answer and an explanation for every question, and a list of the topics to work on.
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