Grade 12 Physical Sciences · Electricity and Magnetism · Paper 1 (Physics)

Electric Circuits Grade 12

Real Electric Circuits past paper questions and answers from 2024 to 2025, with each memo split into the ticks examiners give. Try one, mark yourself, and see exactly which skill cost you marks.

past paper questions: 173 past paper questions
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Question 8.5 · November 2025 · Paper 1 · National (DBE) · 5 marks

Two identical headlights,

L_{1}

and

L_{2}

, and a starter motor, M, of a car are connected to a battery, as shown in the circuit diagram below. The resistance of each headlight is

12 Ω

, while the resistance of the starter motor is

0, 1 Ω

. The emf (

ε

) and internal resistance (r) of the battery are unknown.

The ammeters and the connecting wires have negligible resistance, while the voltmeter has a high resistance. Switches

S_{1}

and

S_{2}

are initially open. Diagram for this question

8.5 Both switches are now closed.

How will the reading on ammeter

A_{1}

be affected? Choose from INCREASES, DECREASES or REMAINS THE SAME.

Explain the answer WITHOUT the use of a calculation.(5)

Work it out on paper first. Then mark yourself with the official memo, one tick at a time.

Electric Circuits skills

Each skill is one thing a memo gives a tick for. Tap one for its own questions, notes and videos.

More Electric Circuits Grade 12 questions and answers

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4. Question 4.2.1 · November 2025 · Paper 1 · National (DBE) · 3 marks
Cricketers at an academy conduct an experiment to determine the relationship between the contact time and the final momentum of a ball for a constant average net force.

A cricket ball of mass $150$ g is thrown horizontally with a certain initial velocity and is struck by a bat so that the ball moves in the opposite direction, as shown in the diagram below. The average net force acting on the ball is horizontal.

The experiment is repeated using the same ball. The average net force and the initial velocity of the ball are kept constant. The contact time between the bat and the ball is changed EACH time. The results obtained are shown in the sketch graph below.
4.2 Calculate the:
4.2.1 Average net force acting on the ball(3)
Show the memo (3 ticks)Memo
1. ✓
  METHOD 1: Change in final momentum (numerator)Gradient $= F_{n e t} = \frac{Δ p _{f}}{Δ ( Δ t )}$
  $= \frac{4 , 5 - 0}{\dots}$
  1 mark · Read a graph of results
2. ✓
  METHOD 1: Change in contact time (denominator) $F_{n e t} = \frac{4 , 5 - 0}{0 , 03 - 0 , 01} = 225$ N
  1 mark · Read a graph of results
3. ✓
  METHOD 1: Answer with direction $F_{n e t} = 225$ N to the right / opposite to the original direction of the ball
  1 mark · Read a graph of results
5. Question 9.2.3 · May/June 2025 · Paper 1 · National (DBE) · 3 marks
9.2 An AC generator produces a maximum output voltage of $340$ V. A $1200$ W electric kettle operates optimally when it is connected to this generator.

Answer the questions that follow.
9.2.3 Calculate the resistance of the kettle.(3)
Show the memo (3 ticks)Memo
1. ✓
  METHOD 1: Formula $R = \frac{V _{r m s}}{I _{r m s}}$
  1 mark · Apply Ohm's law
2. ✓
  METHOD 1: Substitution $= \frac{240 , 42}{4 , 99}$
  1 mark · Apply Ohm's law
3. ✓
  METHOD 1: Answer $R = 48, 18 Ω$
  1 mark · Apply Ohm's law
6. Question 4.1.3 · May/June 2024 · Paper 2 · National (DBE) · 2 marks
4.1 In an experiment, a test tube containing methanol, propanoic acid and a catalyst is heated in a water bath, as shown below.

Write down:
4.1.3 TWO reasons why the use of a water bath is preferred in this experiment(2)
Show the memo (2 ticks)Memo
1. ✓
  First reasonAlcohol/methanol/reactant is flammable/catches fire easily.
  1 mark · Describe and evaluate an experiment
2. ✓
  Second reasonTo heat evenly / a steady, controlled, gradual increase in temperature. (OR: Alcohol/methanol will evaporate too quickly/is volatile.)
  1 mark · Describe and evaluate an experiment
7. Question 8.2.1 · November 2024 · Paper 1 · National (DBE) · 3 marks
$L_{1}$ and $L_{2}$ are two light bulbs that have the following ratings:

$L_{1}$ : $36$ W ; $20$ V and $L_{2}$ : $48$ W ; $32$ V

The two bulbs are connected as shown in the circuit diagram below. The battery has an internal resistance of $0, 6 Ω$ while the conducting wires and the ammeters have negligible resistance. $R_{1}$ and $R_{2}$ are resistors.
8.2 If both light bulbs operate as RATED, calculate the:
8.2.1 Reading on ammeter $A_{2}$ (3)
Show the memo (3 ticks)Memo
1. ✓
  Formula $P = V I$
  1 mark · Calculate electrical power and energy
2. ✓
  Substitution $48 = 32 I$
  1 mark · Calculate electrical power and energy
3. ✓
  Answer $I = 1, 5$ A
  1 mark · Calculate electrical power and energy
8. Question 9.5 · May/June 2024 · Paper 1 · National (DBE) · 3 marks
The simplified diagram below represents an AC generator with a coil rotating clockwise. X and Y are two points in the external circuit.
The total resistance in the external circuit is $42, 4 Ω$ .
9.5 Calculate the maximum current induced.(3)
Show the memo (3 ticks)Memo
1. ✓
  OPTION 1: Formula $I_{ma x} = \frac{V _{ma x}}{R}$
  1 mark · Apply Ohm's law
2. ✓
  OPTION 1: Substitution $I_{ma x} = \frac{125}{42 , 4}$
  1 mark · Apply Ohm's law
3. ✓
  OPTION 1: Answer with unit $I_{ma x} = 2, 95$ A
  1 mark · Apply Ohm's law
9. Question 8.2 · May/June 2024 · Paper 2 · National (DBE) · 2 marks
The relationship between the concentration of the electrolyte and the cell potential is investigated using the following electrochemical cell represented by the cell notation:

Aℓ(s) | $A ℓ^{3 +}$ (aq) || $M^{2 +}$ (aq) | M(s)

The concentration of $M^{2 +}$ is changed and the corresponding emf is measured. The concentration of $A ℓ^{3 +}$ (aq) and the temperature are at standard conditions. The graph below shows the results of this investigation.
8.2 Determine the concentration of $M^{2 +}$ (aq) that will produce an emf of $1, 87$ V.(2)
Show the memo (1 tick)Memo
1. ✓
  Value read from the graph $0, 325$ (mol·dm $^{- 3}$ )
  2 marks · Read a graph of results
10. Question 1.8 · November 2024 · Paper 1 · National (DBE) · 2 marks
1.8 The kilowatt-hour (kWh) is a unit of ...(2)
1. A power.
2. B electric current.
3. C electrical energy.
4. D potential difference.
Show the memo (1 tick)Memo
1. ✓
  Correct optionA kilowatt (kW) is a unit of power and an hour (h) is a unit of time. Power $\times$ time = energy ( $W = P Δ t$ ), so the kilowatt-hour is a unit of energy: $1$ kWh $= 1000$ W $\times 3600$ s $= 3, 6 \times 1 0^{6}$ J.
  
  A is the trap: kWh contains "watt", but it is power multiplied by time.
  
  Answer: C
  2 marks · Calculate electrical power and energy

Electric Circuits Grade 12 videos

Short lessons from South African teachers first. Videos load only when you tap play, to save your data.

Ohm's Law Grade 11 Electric Circuits (Electricity grade 11 & 12)Miss Martins Maths and Science

Electricity Grade 11: Without Internal resistanceKevinmathscience

Grade 11 Electricity: Power (electrical power)Miss Martins Maths and Science

Electricity Grade 11 and 12: Internal resistanceKevinmathscience

Electric circuits Internal resistance Intro: PHYSICS grade 11 and 12Miss Martins Maths and Science

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