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Work through the notes, try the practice questions, then take the quiz. The report tells you exactly what to revise next. (2026)
Wires drawn as straight lines with 90° corners.
Cell = one short, one long line. Battery = two or more cells joined.
Switch = a small break in a line, with a lever.
Bulb (lamp) = circle with a cross.
Fixed resistor = rectangle. Variable resistor = rectangle with an arrow.
Ammeter = circle with A; placed in series. Voltmeter = circle with V; placed in parallel.
Diode = triangle and bar (current flows ONE way only).
LDR and thermistor have arrows pointing IN (showing dependence on light/heat).
Charge Q is measured in coulombs (C).
Current I is the rate of flow of charge: .
1 amp = 1 coulomb per second.
Current needs a closed circuit AND a source of potential difference.
In a series circuit, current is the same at every point.
Conventional current flows from + to −; electrons actually flow the opposite way.
4.2.1.1 — Recognise the standard symbols for common circuit components.
4.2.1.1 — Draw circuit diagrams using straight lines and 90° corners.
4.2.1.1 — Distinguish a cell from a battery (multiple cells).
4.2.1.1 — Place ammeters in series and voltmeters in parallel correctly.
4.2.1.2 — Recall and apply .
4.2.1.2 — Describe current as the rate of flow of charge.
4.2.1.2 — State that current is the same at every point in a single closed loop.
4.2.1.2 — Identify a closed circuit and the role of potential difference in driving current.
4.2.1.3 — Recall and use for any conductor.
4.2.1.3 — Describe AQA RP3 to investigate the resistance of a wire.
4.2.1.3 — Describe how resistance changes with wire length and combinations in series.
4.2.1.3 — Draw and interpret a circuit used to measure resistance.
4.2.1.4 — Sketch and recognise I–V graphs for resistor, filament lamp and diode.
4.2.1.4 — Describe how resistance of a thermistor varies with temperature.
4.2.1.4 — Describe how resistance of an LDR varies with light intensity.
4.2.1.4 — Recall apparatus and method for RP4.
Memorise the 14 symbols. AQA expects you to draw them cleanly and label them correctly.
Below is the full set you need.
Cell = 2 lines; battery = ≥4 lines.
Bulb = circle with a cross; LED has arrows pointing OUT.
Thermistor/LDR have arrows pointing IN (sensing).
Diode lets current flow ONE way; LED is a diode that emits light.
Straight lines, 90° corners, ammeter in series, voltmeter in parallel.
Drawing rules AQA marks reward:
Meter placement (covered in detail in 4.2.1.3):
Mnemonic: Ammeter in series; Voltmeter across.
Diodes and LEDs. Both let current flow only in the direction the triangle points (anode → cathode). The LED also emits light. In a series circuit, putting an LED 'the wrong way' simply prevents current — no light, no damage at safe voltages.
Cells vs batteries. A single cell (e.g. AA = 1.5 V) is drawn as one short and one long line. A 'battery' is two or more cells joined in series — usually drawn as multiple pairs of lines, OR as one cell with broken lines.
Ammeter — in series, low resistance.
Voltmeter — in parallel, high resistance.
Components separated by gaps of wire.
Single cell vs battery (multiple cells).
Common pitfall
Drawing the voltmeter in series. It will read 'mains voltage' and the circuit current will essentially stop because voltmeters have very high resistance.
Current = charge ÷ time. 1 A means 1 coulomb of charge passing a point each second.
Electric charge is a fundamental property of matter — measured in coulombs (C). Electrons carry a tiny negative charge; protons carry the equal positive charge.
Electric current is the rate of flow of charge through a circuit:
So 1 amp = 1 coulomb per second. A 2 A current means 2 C of charge passes any point in the circuit every second.
Worked example. A current of 0.5 A flows for 4 minutes. How much charge has passed?
Worked example (rearranging). 60 C passes through a torch bulb in 30 s. What is the current?
Conditions for current to flow:
Without a closed circuit, charge has nowhere to go. Without a p.d., there's no 'push' to drive the charges.
Q (coulombs) = I (amps) × t (seconds).
1 A = 1 C/s.
Need both a closed loop AND a p.d.
Current is the same at every point in a single-loop circuit.
In a series circuit (single loop, no branches), current is the same at every point — because charge has nowhere else to go.
If the ammeter at the start of the loop reads 0.5 A, the ammeter at any other point will also read 0.5 A.
This is a direct consequence of conservation of charge: charge doesn't pile up or disappear in a wire.
In a parallel circuit (covered in 4.2.2), the rule is different — current splits between branches.
Single loop = current is identical at every point.
Comes from conservation of charge.
If one ammeter reads 0.3 A, ALL ammeters in the same loop read 0.3 A.
Common pitfall
Believing the bulb 'uses up' the current. The bulb uses ENERGY (transferring it from the electrical pathway to thermal/light radiation); the same current returns to the cell.
By convention, current is drawn from + to −. Electrons actually flow the opposite way.
Historically (before electrons were discovered), Benjamin Franklin guessed positive charges were the carriers. He defined current as flowing from + to − terminal. This conventional current convention is still used in all physics diagrams.
We now know that in metal wires, the actual mobile carriers are negatively charged electrons, which drift from − to +. So:
AQA exams use the conventional-current convention. When you draw an arrow on a circuit, it should point from the positive terminal, round the external circuit, to the negative terminal.
Conventional current direction: + to − externally.
Electron drift: − to + (opposite to conventional).
Always use conventional current in AQA diagrams.
Three quantities, one equation — applied in every electricity question.
Potential difference, current and resistance are related by:
Rearranged: and .
Worked example. A 12 V battery drives 0.3 A through a resistor. Find R.
Definitions:
A component obeys Ohm's law if R is constant as V changes. Resistors and wires at constant temperature obey it. Bulbs and diodes do NOT (covered in 4.2.1.4).
V = IR; rearrange as needed.
Volts = J/C; Ohms = V/A.
Ohmic components have constant R; bulbs/diodes are non-ohmic.
Vary the length of a wire; measure V and I; calculate R = V/I; plot R vs L.
Apparatus: length of resistance wire (e.g. constantan or nichrome) taped to a metre rule, two crocodile clips, low-voltage power supply (or cell), ammeter, voltmeter, switch.
Method:
Result: R is directly proportional to L (a straight line through the origin).
Sources of error:
Series-resistor part of RP3. Replace the wire with two resistors in series. Measure total resistance and confirm .
R = V/I.
R ∝ L — straight line through origin.
R adds in series: R_total = R₁ + R₂.
Switch off between readings to keep wire cool.
Straight I–V line through origin = constant R = Ohm's law.
A fixed resistor kept at constant temperature is an ohmic conductor. Its I–V graph is a straight line through the origin:
The gradient gives (so a steeper line means SMALLER resistance).
If you reverse the polarity (negative V), current also reverses — the line continues into the third quadrant.
This linear behaviour requires constant temperature. If the resistor heats up during measurement, R rises and the line curves.
Straight line through origin.
Gradient = 1/R.
Reversal of polarity reverses current symmetrically.
As current rises, the filament heats up; resistance increases; curve flattens.
A filament lamp (incandescent bulb) heats up as more current flows. A hotter metal filament has more vibrating ions colliding with electrons → higher resistance.
I–V graph shape: an S-curve through the origin. Steep near zero (low R when cold), flatter at high |V| (high R when hot).
The lamp is symmetric — reversed voltage produces a mirror-image curve.
This is why a torch bulb feels warm in your hand: a lot of electrical energy is dissipated as thermal store of the filament.
Non-ohmic.
Heating increases R.
S-shaped I–V curve through origin (symmetric).
Almost no current until ~0.6 V forward; then sharp rise. Zero current in reverse.
A diode allows current to flow in only one direction (forward bias). Below ~0.6 V (silicon) almost no current flows. Above 0.6 V, the current rises steeply.
Reverse the polarity: virtually zero current at any negative voltage (until extreme reverse breakdown — not assessed at GCSE).
Diodes are used in rectifiers (converting AC to DC) and many electronic devices.
Diode: one-way current.
Forward turn-on around 0.6 V.
Reverse current ≈ 0.
Sensor resistors used in temperature and light circuits.
Thermistor (NTC type) — resistance DECREASES as temperature rises.
Light-dependent resistor (LDR) — resistance DECREASES as light intensity rises.
Both have characteristic curves: resistance falling smoothly as the sensed quantity (T or light) rises.
Thermistor: R ↓ as T ↑.
LDR: R ↓ as light ↑.
Both used as inputs to control circuits.
Series circuit + variable resistor; sweep V, record I; plot I against V.
Method (for each component):
Expected results: straight line for resistor; S-curve for lamp; one-sided curve for diode.
Note: for the diode, include a protective series resistor to limit current at high V.
Sweep V from negative through zero to positive.
Use a protective resistor when testing diodes.
Allow time between readings to avoid heating drift.
Memorise all 14 standard symbols.
Ammeter — in series, low resistance.
Voltmeter — in parallel, high resistance.
Cell ≠ battery (battery is 2+ cells).
Diode = current one-way; LED is light-emitting diode.
Thermistor and LDR have arrows pointing IN.
Use a ruler for circuit diagrams in the exam.
Q = It; charge in coulombs, current in amps, time in seconds.
1 amp = 1 coulomb per second.
Current requires a closed circuit AND a potential difference.
Series circuits: current is the same at every point.
Conventional current flows from + to − externally; electrons actually flow oppositely.
When drawing, leave space between components — squashed diagrams lose marks.
Don't add arrowheads to wires.
Label cell voltage on the symbol (e.g. '6 V').
If the question asks for a meter, use the correct symbol — A or V inside a circle.
Practise drawing the LDR and thermistor — these are commonly forgotten.
Always convert minutes/hours to seconds before applying Q = It.
Quote answers in coulombs (C) or amps (A) — never just 'C/s' or other variants.
If a question shows two ammeters in series, both will read the same — don't assume otherwise.
For Foundation tier, draw an arrow from + to − on the circuit if asked to show current direction.
Show working: write 'V = IR', then substitute, then solve.
Sources: AQA GCSE Physics 8463 specification — section 4.2.1.1 Standard circuit symbols; AQA GCSE Physics 8463 Examiner Reports 2022–2024; AQA GCSE Physics 8463 specification — section 4.2.1.2 Electrical charge and current; AQA Examiner Report 2024 Paper 1; AQA GCSE Physics 8463 specification — section 4.2.1.3; AQA Required Practical 3 handbook; AQA Paper 1 Examiner Reports 2022–2024; AQA GCSE Physics 8463 specification — section 4.2.1.4 Resistors; AQA Required Practical 4 handbook · Last reviewed 2026-05-25 · AQA GCSE · Physics 8463 Higher & Foundation Tier