AQA GCSE: Physics

Simple Electric Circuits

  • Current (I): flow of charge (amps, A)

  • Voltage (V): energy transferred per charge (volts, V)

  • Resistance (R): opposition to current (ohms, Ω)

  • Series circuits:

    • Same current everywhere

    • Voltage shared

    • Total resistance = sum

  • Parallel circuits:

    • Same voltage

    • Current splits

    • Lower total resistance

Atoms and Materials

Atomic Structure

  • Proton (+1), neutron (0), electron (–1)

  • Nucleus contains protons & neutrons

  • Electrons in shells

States of Matter

  • Solid → fixed shape & volume

  • Liquid → fixed volume, no fixed shape

  • Gas → no fixed shape or volume

Changes of State

  • Melting, freezing, evaporation, condensation, sublimation

  • Internal energy = kinetic + potential energy of particles

Forces

Types of Forces

  • Gravity, friction, air resistance, tension, normal contact force

Electricity in the Home

  • UK mains supply: 230 V AC, 50 Hz

  • Live wire: brown

  • Neutral wire: blue

  • Earth wire: green/yellow (safety)

  • Fuse: melts if current too high → breaks circuit

  • Double insulation: plastic casing, no earth needed

Energy Resources

Renewable

  • Solar, wind, hydro, tidal, geothermal, biofuel

Non-renewable

  • Coal, oil, gas, nuclear

Energy Stores

  • Thermal, kinetic, chemical, gravitational, elastic, nuclear

Power Stations

  • Fuel → boil water → steam → turbine → generator

Atoms and Radiation

Isotopes

  • Same protons, different neutrons

Radiation Types

Type

What it is

Stopped by

Ionising

Alpha (α)

2p + 2n

Paper/skin

Very

Beta (β)

Electron

Aluminium

Medium

Gamma (γ)

EM wave

Lead/concrete

Weak

Half-life

  • Time taken for radioactive substance to halve in activity

Uses

  • Medical tracers, cancer treatment, smoke detectors, carbon dating

Risks

  • Cell damage, mutations, cancer

Waves

Types

  • Transverse: oscillations perpendicular (light, water)

  • Longitudinal: oscillations parallel (sound)

Wave Properties

  • Amplitude, wavelength, frequency, speed

Reflection & Refraction

  • Reflection → bouncing off surface

  • Refraction → bending when entering different medium

Sound Waves

  • Longitudinal, need medium, faster in solids

Uses & Dangers

  • Microwaves → cooking

  • Infrared → heaters

  • UV → sterilising (skin damage risk)

  • X-rays → medical imaging

  • Gamma → cancer treatment

Key Formula List