Physics (AS & A Level) revision notes

One chapter for each section of the 9702 syllabus, with worked examples. Read a chapter, then practise it with real past-paper questions.

1. 1Physical quantities and unitsMagnitudes and units, reasonable estimates, SI base units and prefixes, checking equations for homogeneity, systematic and random errors, precision and accuracy, combining uncertainties, and adding and resolving vectors.7 min read
2. 2KinematicsDistance, displacement, speed, velocity and acceleration, what the gradients and areas of motion graphs mean, the equations of uniformly accelerated motion, measuring g, and projectiles.4 min read
3. 3DynamicsMass and weight, F = ma, momentum, force as rate of change of momentum, Newton's laws, drag and terminal velocity, conservation of momentum, and elastic and inelastic collisions.5 min read
4. 4Forces, density and pressureCentre of gravity, moments, couples and torque, the principle of moments and equilibrium, vector triangles, density, pressure, hydrostatic pressure and upthrust.5 min read
5. 5Work, energy and powerWork done by a force, conservation of energy, efficiency, power and P = Fv, and deriving and using the formulas for gravitational potential energy and kinetic energy.4 min read
6. 6Deformation of solidsTensile and compressive forces, Hooke's law and the spring constant, stress, strain and the Young modulus and how to measure it, elastic and plastic behaviour, and the energy stored in a stretched material.5 min read
7. 7WavesWave terms, using a CRO, v = f lambda, intensity, transverse and longitudinal waves, the Doppler effect for a moving source, the electromagnetic spectrum, and polarisation with Malus's law.6 min read
8. 8SuperpositionThe principle of superposition, stationary waves on strings, in air columns and with microwaves, nodes and antinodes, diffraction, coherence and two-source interference, and the diffraction grating.6 min read
9. 9ElectricityCurrent as a flow of charge carriers, quantised charge, I = Anvq, potential difference and power, resistance, I-V characteristics, Ohm's law, resistivity, LDRs and thermistors.4 min read
10. 10D.C. circuitsCircuit symbols, e.m.f. against p.d., internal resistance, Kirchhoff's laws, resistors in series and parallel, potential dividers, potentiometers, galvanometers and null methods, and sensors using LDRs and thermistors.5 min read
11. 11Particle physicsThe alpha-scattering experiment, the nuclear atom, nuclide notation and isotopes, alpha, beta and gamma radiation, antiparticles and neutrinos, decay equations, quarks, hadrons and leptons.4 min read
12. 12Motion in a circleThe radian, angular displacement and angular speed, v = r omega, centripetal acceleration and centripetal force, and how to solve circular motion problems.4 min read
13. 13Gravitational fieldsGravitational field strength and field lines, Newton's law of gravitation, circular orbits and geostationary satellites, g = GM/r squared, gravitational potential, and gravitational potential energy.5 min read
14. 14TemperatureThermal equilibrium, thermometric properties, the thermodynamic scale and absolute zero, converting kelvin and Celsius, specific heat capacity, and specific latent heat of fusion and vaporisation.4 min read
15. 15Ideal gasesThe mole and the Avogadro constant, the ideal gas equation in both forms, the Boltzmann constant, the assumptions of kinetic theory, deriving pressure from molecular motion, root-mean-square speed, and mean kinetic energy.4 min read
16. 16ThermodynamicsInternal energy as the sum of random kinetic and potential energies, why a temperature rise means more internal energy, work done when a gas changes volume, and the first law of thermodynamics.4 min read
17. 17OscillationsOscillation terms and angular frequency, the defining equation of simple harmonic motion, displacement, velocity and acceleration equations and graphs, energy interchange, damping, and resonance.5 min read
18. 18Electric fieldsElectric field strength and field lines, uniform fields between parallel plates and how charged particles move in them, Coulomb's law, the field of a point charge, electric potential and potential gradient, and electric potential energy.4 min read
19. 19CapacitanceCapacitance of isolated spheres and parallel plates, capacitors in series and parallel, energy stored from the area under a graph, and exponential discharge through a resistor with the time constant RC.4 min read
20. 20Magnetic fieldsMagnetic fields and field lines, the force on a current and on a moving charge, Fleming's left-hand rule, the Hall voltage, circular paths and velocity selection, field patterns of currents, forces between conductors, and electromagnetic induction with Faraday's and Lenz's laws.6 min read
21. 21Alternating currentsPeriod, frequency and peak value, sinusoidal equations, r.m.s. values and mean power, half-wave and full-wave rectification with diodes, and smoothing with a capacitor.4 min read
22. 22Quantum physicsPhotons and E = hf, the electronvolt, photon momentum, the photoelectric effect and Einstein's equation, threshold frequency and work function, wave-particle duality and the de Broglie wavelength, and energy levels with line spectra.5 min read
23. 23Nuclear physicsMass-energy equivalence, nuclear equations, mass defect and binding energy, binding energy per nucleon, fusion and fission, the random nature of decay, activity and the decay constant, half-life, and exponential decay.4 min read
24. 24Medical physicsThe piezoelectric transducer, ultrasound reflection, acoustic impedance and the intensity reflection coefficient, attenuation, producing X-rays and minimum wavelength, contrast, CT scanning, tracers, annihilation, and PET scanning.6 min read
25. 25Astronomy and cosmologyLuminosity and radiant flux intensity, the inverse square law, standard candles, Wien's displacement law, the Stefan-Boltzmann law and estimating a star's radius, redshift, the expanding Universe, Hubble's law and the Big Bang.5 min read