Unit 1: Thermal, nuclear and electrical physics
12 dot points, in syllabus order. Each dot point has a focused answer, with exam-style questions and worked answers where available.
Topic 1: Heating processes
Internal energy and thermal equilibrium. Defines internal energy as the sum of microscopic kinetic and potential energies, distinguishes heat (energy in transit) from temperature (average translational kinetic energy of particles), and explains how thermal equilibrium establishes a common temperature.
Heat transfer mechanisms. Defines conduction (particle-to-particle collisions), convection (bulk fluid motion driven by density differences) and radiation (electromagnetic emission), and works the QCAA-style application question on insulation and energy-efficient homes.
Specific heat capacity and latent heat. Applies and to heating, cooling and phase-change calculations, and works the QCAA-style multi-stage problem (heating ice, melting, heating water, vaporising) used in EA Paper 1.
Topic 2: Ionising radiation and nuclear reactions
Fission and fusion. Reads the binding-energy curve to show why both reactions release energy, applies to mass defect, and works the QCAA-style energy-per-reaction problem from EA Paper 2 with worked U-235 numbers.
Three common types of ionising radiation. Tabulates the charge, mass, ionising power, penetration and shielding of alpha, beta and gamma radiation, and works the QCAA-style balanced-nuclear-equation problem that appears in EA Paper 1.
Half-life and radioactive decay. Applies and the decay constant , walks through radiometric dating (carbon-14) and medical applications (technetium-99m), and works the QCAA-style number-of-half-lives problem.
Topic 3: Electrical circuits
Ohm's law. Defines current (), potential difference () and resistance (), distinguishes ohmic and non-ohmic conductors, and works the QCAA-style multi-resistor calculation from EA Paper 1.
Electrical power and energy. Applies , and , distinguishes power from energy, converts kWh to joules, and works the QCAA-style household appliance running-cost problem.
Series and parallel circuits. Applies Kirchhoff's current law (junction rule) and voltage law (loop rule), derives equivalent resistance for series and parallel combinations, and works the QCAA-style mixed-circuit problem from EA Paper 2.
How are electric circuits analysed using Ohm's law and energy conservation?
How are thermal phenomena explained using kinetic theory and heat transfer?
What is nuclear physics, and how do nuclei decay and produce energy?
