AQA GCSE Combined Science: Trilogy Physics Paper 1 (Foundation), 2022: Question 1

12 marks · Standard Demand difficulty · Short Answer

Analyze a filament lamp circuit to identify components, calculate mean current, power, and resistance, and determine I-V characteristics.

Practise this question

Question

A multi-part physics exam question about a filament lamp circuit. It includes a circuit diagram (Figure 1) showing a battery, variable resistor, ammeter, and filament lamp with a voltmeter connected in parallel. Question 01.1 asks to identify a battery symbol. 01.2 asks which component adjusts potential difference. 01.3 deals with correcting a zero error on a voltmeter. 01.4 provides a table of current readings (0.54, 0.58, 0.53) and asks for the mean. 01.5 and 01.6 require calculating power and resistance using provided formulas. 01.7 is a fill-in-the-blanks about temperature and resistance. 01.8 asks to identify the correct I-V characteristic graph for a filament lamp from three options.
Question text

01 A student investigated how the potential difference across a filament lamp affects the

current in the lamp.

Figure 1 shows the circuit the student used.

Figure 1

01.1 Figure 2 shows a circuit symbol.

Figure 2

What component does the symbol represent?

[1 mark]

Tick ( ) one box.

Ammeter

Battery

Lamp

Variable resistor 3

01.2 Which component from Figure 1 did the student use to adjust the potential difference

across the lamp?

[1 mark]

01.3 When the voltmeter was not connected to the circuit it gave a reading of 0.4 volts.

How can the student correct all the readings taken from the voltmeter?

[1 mark]

Tick ( ) one box.

Add 0.4 volts to each reading

Divide each reading by 0.4 volts

Multiply each reading by 0.4 volts

Subtract 0.4 volts from each reading4

01.4 The student recorded three values of current for each potential difference.

Table 1 shows the results for 2.5 volts.

Table 1

Potential difference Current in amps

in volts

12 3

2.5 0.54 0.58 0.53

Calculate the mean current in the lamp.

[2 marks]

Mean current = A

*0031.*5 Calculate the power of the lamp when the potential difference across the lamp

was 4.8 V

The current in the lamp was 0.75 A

Use the equation:

power = potential difference × current

[2 marks]

5 Power = W

01.6 Calculate the resistance of the lamp when the potential difference across the lamp

was 4.8 V

The current in the lamp was 0.75 A

Use the equation:

potential difference

*04* resistance =

current

[2 marks]

Resistance = Ω

01.7 Complete the sentence.

Choose answers from the box.

Each answer may be used once, more than once or not at all.

[2 marks]

decrease increase stay the same

Increasing the current in a filament lamp makes the temperature

of the lamp and the

resistance of the lamp 6 .

01.8 Which graph shows the relationship between potential difference and current for a

filament lamp?

[1 mark]

Tick ( ) one box.

Mark scheme

Show the mark scheme The mark scheme for question 1, totaling 12 marks. It specifies: 01.1 is battery; 01.2 is variable resistor; 01.3 is subtract 0.4 volts; 01.4 shows the mean calculation (0.54+0.58+0.53)/3 = 0.55 A; 01.5 shows power calculation 4.8 x 0.75 = 3.6 W; 01.6 shows resistance calculation 4.8 / 0.75 = 6.4 ohms; 01.7 requires 'increase' for both blanks; 01.8 identifies the S-shaped curve as the correct graph. Each part includes AO and specification references.

Question 1

AO /

Question Answers Extra information Mark

Spec. Ref.

01.1 battery 1 AO1

6.2.1.1

AO /

Spec. Ref.

01.2 variable resistor allow resistor 1 AO1

allow battery / cells 6.2.2

allow correct circuit symbol

AO /

Spec. Ref.

01.3 subtract 0.4 volts from each 1 AO1

reading 6.2.1.4

AO /

Spec. Ref.

01.4 0.54+0.58+0.53 1.65 1 AO2

mean = allow mean =

3 6.2.1.3

mean = 0.55 (A)

AO /

Spec. Ref.

01.5 P = 4.8 × 0.75 1 AO2

6.2.4.1

P = 3.6 (W) 1

AO /

Spec. Ref.

01.6 4.8 1 AO2

R =

0.75 6.2.1.3

R = 6.4 (Ω) 1

AO /

Spec. Ref.

01.7 increase 1 AO1

6.2.1.4

increase 1

AO /

Spec. Ref.

01.8 1 AO1

6.2.1.4

Total Question 1 12

How to answer it

Investigating a Filament Lamp

What this question tests

This question assesses your ability to identify circuit symbols and components, handle experimental errors (zero errors), calculate means, use standard electrical equations (P=VI and V=IR), and describe the physical characteristics of a filament lamp.

Parts 01.1 & 01.2

Circuit Symbols and Components

Correct Answers

  • 01.1: Battery
  • 01.2: Variable resistor

Key Knowledge

A battery consists of two or more cells connected in series. A variable resistor (the box with a diagonal arrow) allows you to change the resistance, which in turn changes the current and potential difference in the circuit.

Examiner Tip: For 01.2, the mark scheme also accepts "resistor" or "battery/cells" as these also affect the potential difference, but "variable resistor" is the most accurate answer based on the diagram.
Part 01.3

Handling Systematic Errors

Correct Answer

Subtract 0.4 volts from each reading.

Exam Technique

This is a zero error. If a piece of equipment shows a value when it should be zero, you must subtract that "false" value from every reading you take to get the true result.

Part 01.4

Calculating the Mean

Step-by-Step Calculation

  1. Add the three current values together:
    0.54 + 0.58 + 0.53 = 1.65
  2. Divide the total by the number of readings (3):
    1.65 ÷ 3 = 0.55

Mean current = 0.55 A

Common Calculation Trap

If you type 0.54 + 0.58 + 0.53 ÷ 3 into a calculator without pressing '=' first, the calculator will only divide the last number by 3. Always find the total first!

Parts 01.5 & 01.6

Using Electrical Equations

01.5: Power Calculation

Equation: power = p.d. × current

  1. Substitute: 4.8 × 0.75
  2. Calculate: 3.6

Power = 3.6 W

01.6: Resistance Calculation

Equation: resistance = p.d. ÷ current

  1. Substitute: 4.8 ÷ 0.75
  2. Calculate: 6.4

Resistance = 6.4 Ω

Note: Even if the equation is provided, you earn 1 mark for the correct substitution and 1 mark for the final answer. Never skip the working!
Part 01.7

Filament Lamp Properties

Completed Sentence

Increasing the current in a filament lamp makes the temperature of the lamp increase and the resistance of the lamp increase.

Key Knowledge

As current increases, more electrons flow through the metal filament. They collide with the metal ions, causing them to vibrate more. This makes the filament hotter (temperature increases) and makes it harder for electrons to pass through (resistance increases).

Part 01.8

I-V Characteristics (Graphs)

Correct Graph

The first graph (the "S-shaped" curve passing through the origin).

How to identify it

A filament lamp is non-ohmic. Because its resistance increases as it gets hotter, the graph curves. It should look like a shallow "S" shape, showing that as potential difference increases, the current does not increase at a constant rate.

Common Error

Do not pick the straight line! A straight line through the origin represents a fixed resistor at a constant temperature (Ohmic conductor).

Topics

Physics · P2: Electricity

Question and mark scheme from the AQA GCSE Combined Science: Trilogy examination, Physics Paper 1 (Foundation), 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.