WJEC A Level Physics
WJEC A Level Physics Unit 3: Oscillations and Nuclei Exam Questions
Free WJEC A Level Physics exam questions for Unit 3: Oscillations and Nuclei, with a mark scheme for every pack. Covers circular motion, simple harmonic motion and resonance, kinetic theory and ideal gases, thermodynamics, radioactive decay and nuclear energy.
Unit 3: Oscillations and Nuclei exam questions
5 question packs of real past exam questions, each with its mark scheme. Do not stop after a few: answer as many as you can without notes, then mark every answer with the mark scheme. The more questions you do, the more quickly you will spot how examiners ask about each idea.
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A-Level Physics Flashcards for 2027 Onwards
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Then test yourself with the questions on this page.
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About WJEC A Level Physics Unit 3: Oscillations and Nuclei
Unit 3 of WJEC A Level Physics, Oscillations and Nuclei, is the first A2 unit. It covers circular motion, simple harmonic motion with damping and resonance, the kinetic theory of gases, internal energy and the first law of thermodynamics, radioactive decay and half-life, and nuclear energy including binding energy, fission and fusion. It extends the mechanics and particle physics of Unit 1. Examiners test centripetal force problems, SHM equations and graphs, ideal gas and work done calculations, exponential decay with the decay constant, and mass-energy calculations using atomic mass units.
What you need to know
- 3.1 Angular velocity omega = 2 pi / T, centripetal acceleration v^2 / r = omega^2 r and centripetal force as the resultant force.
- 3.2 SHM defined by a = -omega^2 x, x = A cos(omega t + epsilon), velocity and acceleration graphs, period of a mass-spring system and pendulum, energy in SHM, damping, forced oscillations and resonance.
- 3.3-3.4 Ideal gas equation pV = nRT, kinetic theory assumptions and p = 1/3 rho c^2, internal energy of an ideal gas U = 3/2 nRT, the first law Delta U = Q - W, work done W = p Delta V, and specific heat capacity.
- 3.5 Properties of alpha, beta and gamma radiation, background radiation, decay equations, random and spontaneous decay, A = lambda N, half-life and exponential decay.
- 3.6 E = mc^2, mass defect, binding energy per nucleon curve, energy released in fission and fusion, and conversion using 1 u = 931 MeV.
Common mistakes in Unit 3: Oscillations and Nuclei
- Saying the acceleration in SHM is greatest at the equilibrium position. Acceleration is greatest at maximum displacement and zero at equilibrium, where speed is greatest.
- Using root mean square speed as the average speed. c rms is the square root of the mean of the squared speeds, which differs from the mean speed.
- Forgetting to convert half-life into seconds when calculating activity from A = lambda N. lambda must be in s-1 for activity in becquerels.
- Stating that internal energy of an ideal gas includes potential energy. In an ideal gas there are no intermolecular forces, so internal energy is only kinetic.
- Saying fission releases energy because mass is created. Mass is lost (mass defect) and the products have higher binding energy per nucleon.
Try three Unit 3: Oscillations and Nuclei exam-style questions
1. Calculate the internal energy of 2.0 mol of an ideal monatomic gas at 300 K. (2 marks)
Show the mark scheme answer
U = 3/2 nRT = 1.5 x 2.0 x 8.31 x 300; = 7.5 x 10^3 J.
2. The mass defect of a helium-4 nucleus is 0.0304 u. Calculate its binding energy in MeV and the binding energy per nucleon. (2 marks)
Show the mark scheme answer
0.0304 x 931 = 28.3 MeV; 28.3 / 4 = 7.1 MeV per nucleon.
3. Explain what is meant by resonance and describe the effect of damping on it. (3 marks)
Show the mark scheme answer
Resonance occurs when the driving frequency equals the natural frequency, giving maximum amplitude; damping reduces the maximum amplitude; and broadens the peak, with the resonant frequency slightly lower.
Unit 3: Oscillations and Nuclei FAQs
What does WJEC A Level Physics Unit 3: Oscillations and Nuclei cover?
Circular motion, vibrations, kinetic theory, thermal physics, nuclear decay and nuclear energy.
Is Unit 3 an AS or A2 unit?
Unit 3 is an A2 unit assessed by a written exam, and it can draw on AS content.
How should I revise SHM for Oscillations and Nuclei?
Sketch displacement, velocity and acceleration against time on aligned axes, learn which equations are in the data booklet, and practise energy exchange questions.
