PHYSICS PAPER 1 PRACTICAL

• Investigating factors affecting resistance of electrical circuits

  1. Use battery, ammeter, voltmeter, and wire

  2. Measure current and potential difference

  3. Calculate resistance using formula: R = V/I

  4. Vary length of wire

  5. Plot graph of resistance vs length
• Investigating the effectiveness of thermal insulators

  1. Place a small beaker inside a larger beaker

  2. Use a kettle to boil water

  3. Transfer 80 cm^3 of hot water into the small beaker

  4. Use a piece of cardboard as a lid for the large beaker with a hole for a thermometer

  5. Place the thermometer through the hole with the bulb in the hot water

  6. Record the starting temperature and start a stopwatch

  7. Record the temperature every 3 minutes for 15 minutes

  8. Repeat the experiment using an insulating material (e.g. bubble wrap) between the beakers

  9. Test a range of insulating materials (e.g. cotton wool, polystyrene balls)

  10. Use the same mass of insulating material in each case
• Investigating how the thickness of a material affects thermal insulation

  1. Start with a beaker containing 80 cm^3 of hot water

  2. Measure the temperature of the water every 3 minutes for 15 minutes

  3. Repeat the experiment with 2 layers of newspaper around the beaker

  4. Repeat the experiment with 4 layers and 6 layers of newspaper

  Dependent variable: Temperature of water

  Independent variable: The no. of layers of newspaper
• Required practical


  At least 15% of the marks in your exam will come from questions relating to required practicals
• Factors affecting the resistance of electrical circuits


  • Length of a wire
• Equipment used


  • Battery
  • Ammeter
  • Voltmeter
  • Length of wire
• Measuring resistance in the circuit

  1. Use ammeter to measure current

  2. Use voltmeter to measure potential difference

  3. Calculate resistance using R=V/I
• Increasing length of wire

  Increases resistance
• Graph of resistance vs length

  • Straight line passing through zero
  • Indicates resistance is directly proportional to length
• There is a small resistance when the length of the wire is zero
• Zero error


  A reading on a measuring instrument when the value should be zero, a systematic error
• Zero error is caused by the equipment, e.g. difficulty getting crocodile clip at zero position, resistance from contact between clip and wire</b>
• Heating effects can affect the resistance measurement
• Reducing heating effects


  • Use low potential difference to keep current low
  • Only turn on current when taking readings, turn off between readings
• Variable resistor


  Contains a long piece of wire in a coil, using a slider to change the length of wire the current runs through
• Increasing resistance in a variable resistor


  Makes the lamp dimmer