AQA GCSE Physics Physics Paper 1 (Higher), November 2021: Question 1

10 marks · Low Demand difficulty · Short Answer

Define direct potential difference, identify and apply electrical and power equations to calculate charging time, motor resistance, and compare charging systems.

Practise this question

Question

Figure 1 shows a photograph of an electric car connected to a charging station by a power cable. The question consists of six parts: 01.1 asks what 'direct potential difference' means; 01.2 has four tick boxes to choose the formula linking energy transferred, power, and time; 01.3 asks to calculate the time to charge a battery storing 162 000 000 J with a power of 7200 W; 01.4 has four tick boxes to choose the equation relating current, potential difference, and resistance; 01.5 asks to calculate resistance when potential difference is 480 V and current is 15 A; 01.6 gives details for charging system A (13 A, 230 V) and system B (26 A, 230 V) and asks how the charging times compare using three tick boxes.
Question text

01 Figure 1 shows an electric car being recharged.

Charging station

Figure 1

Power cable

01.1 The charging station applies a direct potential difference across the battery of the car.

What does ‘direct potential difference’ mean?

[1 mark]

01.2 Which equation links energy transferred (E), power (P) and time (t)?

[1 mark]

Tick ( ) one box.

power

energy transferred =

time

time

energy transferred =

power

energy transferred = power × time

energy transferred = power2 × time

01.3 The battery in the electric car can store 162 000 000 J of energy.

The charging station has a power output of 7200 W.

Calculate the time taken to fully recharge the battery from zero.

[3 marks]

5Time taken = s

01.4 Which equation links current (I), potential difference (V) and resistance (R)?

[1 mark]

Tick ( ) one box.

I = V × R

I = V 2 × R

R = I × V

V = I × R

01.5 The potential difference across the battery is 480 V.

There is a current of 15 A in the circuit connecting the battery to the motor of the

electric car.

Calculate the resistance of the motor.

[3 marks]

Resistance = Ω

01.6 Different charging systems use different electrical currents.

• Charging system A has a current of 13 A.

• Charging system B has a current of 26 A.

• The potential difference of both charging systems is 230 V.

How does the time taken to recharge a battery using charging system A compare with

the time taken using charging system B?

[1 mark]

Tick ( ) one box.

Time taken using system A is half the time of system B

Time taken using system A is the same as system B

Time taken using system A is double the time of system B

Mark scheme

Show the mark scheme Mark scheme table for Question 1: 01.1 awards 1 mark for 'the polarity (of the supply) does not change' or 'potential difference in one direction (only)'; 01.2 awards 1 mark for ticking 'energy transferred = power × time'; 01.3 awards 3 marks for substitution (162 000 000 = 7200 × t), rearrangement (t = 162 000 000 / 7200), and answer (22 500 s); 01.4 awards 1 mark for 'V = I × R'; 01.5 awards 3 marks for substitution (480 = 15 × R), rearrangement (R = 480 / 15), and answer (32 Ω); 01.6 awards 1 mark for 'time taken using system A is double the time of system B'. Total: 10 marks.

Question 1

AO /

Question Answers Extra information Mark

Spec. Ref.

the polarity (of the supply) does allow potential difference in one

01.1 1 AO1

not change direction (only)

4.2.3.1

01.2 energy transferred = power × 1 AO1

time 4.1.1.4

4.2.4.2

01.3 162 000 000 = 7200 × t 1 AO2

4.1.1.4

4.2.4.2

162 000 000 1

t =

7200

t = 22 500 (s) 1

01.4 V = I × R 1 AO1

4.2.1.3

01.5 480 = 15 × R 1 AO2

4.2.1.3

480 1

R =

R = 32 (Ω) 1

01.6 time taken using system A is 1 AO3

double the time of system B 4.2.4.1

Total 10

How to answer it

Electric Car Charging: Circuits, Power & Resistance

What This Question Tests

Core foundational electricity and energy transfer knowledge from AQA GCSE Physics (Paper 1):

  • Recall & Concepts: Defining direct potential difference (d.c.) and identifying standard circuit formulae for power and resistance.
  • Mathematical Skills: Rearranging equations ( E = P × t and V = I × R ), substituting large values accurately, and direct proportional reasoning.

Question 01.1 1 Mark

Definition of Direct Potential Difference

✅ Mark Scheme Answer

Any one of the following:

  • The polarity (of the supply) does not change.
  • Potential difference is in one direction only.
Award 1 mark for either statement.

💡 Key Knowledge

d.c. (Direct Current): Current and potential difference remain in a single direction (e.g. batteries, cells).

a.c. (Alternating Current): Direction of potential difference and current constantly reverses (e.g. UK mains electricity at 50 Hz, 230 V).

❌ Common Errors

  • Vague everyday descriptions such as "it goes straight into the car without stopping".
  • Confusing potential difference with current without specifying direction.

Question 01.2 1 Mark

Equation Linking Energy Transferred (E), Power (P), and Time (t)

✅ Correct Answer

Tick box 3:

energy transferred = power × time

1 mark for the correct box ticked.

🧠 Exam Technique

Recall the definition of power: Power is the rate of energy transfer:

Power = Energy ÷ Time

Rearranging by multiplying both sides by time gives:
Energy = Power × Time (or E = P × t ).

Question 01.3 3 Marks

Calculating Time to Recharge Battery

📐 Step-by-Step Calculation

Given: Energy E = 162 000 000 J , Power P = 7200 W

  1. Substitute into formula:
    162 000 000 = 7200 × t
    1 mark
  2. Rearrange to make time (t) the subject:
    t = 162 000 000 ÷ 7200
    1 mark
  3. Calculate final value:
    t = 22 500 s
    1 mark

❌ Common Errors & Traps

  • Counting zeros: Entering too few or too many zeros into the calculator (e.g. writing 16.2 million instead of 162 million).
  • Unnecessary conversions: Converting seconds to hours. The answer line specifically asks for s , so leave it in seconds!
  • Incorrect rearrangement: Dividing 7200 by 162 000 000.

Question 01.4 1 Mark

Equation Linking Current (I), Potential Difference (V), and Resistance (R)

✅ Correct Answer

Tick box 4:

V = I × R

1 mark for the correct box ticked.

💡 Key Knowledge

This is Ohm's Law. Learn all three arrangements:

  • V = I × R
  • I = V ÷ R
  • R = V ÷ I

Question 01.5 3 Marks

Calculating Motor Resistance

📐 Step-by-Step Calculation

Given: V = 480 V , Current I = 15 A

  1. Substitute values:
    480 = 15 × R
    1 mark
  2. Rearrange for R:
    R = 480 ÷ 15
    1 mark
  3. Calculate final answer:
    R = 32 Ω
    1 mark

🧠 Exam Technique

  • Always write the substitution step before rearranging. If you make a math error later, you still secure the substitution mark.
  • Check unit consistency: Volts (V) and Amperes (A) give Ohms (Ω) directly. No unit prefixes (like mA or kV) needed converting here.

Question 01.6 1 Mark

Comparing Charging Times for Two Systems

✅ Correct Answer

Tick box 3:

Time taken using system A is double the time of system B

1 mark for the correct box ticked.

🧠 Why This is True (Proportional Reasoning)

  • Both systems have the same potential difference ( V = 230 V ).
  • Power transferred is P = V × I .
  • System B has twice the current of system A ( 26 A = 2 × 13 A ), so System B charges with twice the power.
  • Delivering the same total energy at half the power means system A takes twice as long (double the time).

❌ Common Errors

Confusing inverse proportionality: thinking that because system A has half the current, it takes half the time. Remember: lower current means a slower charge!

Topics

Physics · P1: Energy · P2: Electricity

Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 1 (Higher), November 2021. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.