Resistor Networks - AQA Practical

AQA GCSE Physics Electricity required practical: evaluating resistance of resistors in series and parallel.‍ ‍Combined & Triple Science.

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Plan a valid method to investigate how the total resistance of two resistors varies when arranged in series and parallel.

[6 marks]

1. Prepare

• What basic components do we connect?

  • 1.5 V cell to power the circuit

  • Switch

  • First Resistor

• What components do we add to measure current and voltage?

  • Ammeter in series

  • Voltmeter in parallel

2. Record Readings

• What readings do we take for the first resistor?

  • Current in Amps

  • Voltage (Potential Difference) in Volts

• Remember, we're testing two resistors!

  Replace R₁ with R₂

  Take:

  • Current in Amps

  • Voltage (Potential Difference) in Volts

  Make sure to turn off switch when changing resistors, then turn it back on to take readings.

3. Calculate

• How do we calculate the resistance of each resistor?

  • R = V / I

4. Compare 2 Arrangements

• What is the first arrangement?

  • Place resistors in series

  • Close switch and take current and voltage readings

  • Calculate resistance

• What's the second arrangement?

  • Open switch

  • Place resistors in parallel

  • Close switch and take current and voltage readings

  • Calculate resistance

Challenge:

• What are the CONTROL variables in this practical?

  Keep the same two resistors and power supply throughout the investigation.

• When the values are compared, what conclusion is made?

  In Series

  • Total resistance = sum of the resistance of both resistors

  In Parallel

  • Total resistance is less than each individual resistor

  • This is because the current has an alternative path in parallel circuits, so more current flows (greater total current for the same potential difference, reducing resistance).

Continue Revising Paper 1

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