GCSE Physics Required Practicals (AQA Paper One)

Overview

• Focus on key practicals for AQA paper one:
  • Insulation (separate science only)
  • Specific heat capacity
  • Resistance of a wire
  • Current-voltage characteristics
  • Density
• Discussion includes method, variables, graphs, accuracy, safety, and variations in equipment/methods.

Specific Heat Capacity

• Definition: Energy needed to increase temperature of 1 kg of a substance by 1°C.
• Equation: E = m × c × Δθ
  • E = energy (Joules)
  • m = mass (kg)
  • c = specific heat capacity
  • Δθ = change in temperature
• Units: Energy (J) / Mass (kg) / Temperature (°C)
• Method:
  1. Measure mass of the substance.
  2. Measure initial temperature.
  3. Switch on heater, place in substance, start stopwatch.
  4. Record temperature and energy change every 2 minutes.
  5. Use rearranged equation to find specific heat capacity.
• Graphs: Plot temperature vs. time.
• Safety: Avoid touching hot heater.
• Accuracy: Use insulation to minimize energy loss.

Resistance of a Wire

• Objective: Study how resistance changes with wire length.
• Method:
  1. Set up circuit with power source, ammeter, voltmeter, and wire.
  2. Measure resistance at various lengths using R = V/I.
  3. Increase wire length, measure new readings.
• Graph: Plot length vs. resistance (directly proportional).
• Errors & Safety: Avoid wire heating up by disconnecting between readings. Avoid parallax error.

Current-Voltage Characteristics

• Objective: Determine how current and voltage vary across components.
• Components: Fixed resistor, filament bulb, diode.
• Method:
  1. Set up circuit with ammeter, voltmeter, and variable resistor.
  2. Measure current and PD, adjust variable resistor.
  3. Reverse cell connections for negative values.
• Graphs:
  • Fixed resistor: Linear, directly proportional.
  • Filament bulb: Non-linear, resistance increases with temperature.
  • Diode: Current flows in one direction.
• Safety: Disconnect between readings to prevent heating.

Density

• Objective: Calculate density by measuring mass and volume.
• Regular Solids:
  • Measure mass with a balance.
  • Measure dimensions with a ruler, calculate volume.
• Irregular Solids:
  • Use displacement can (Eureka can) to measure volume.
• Liquids:
  • Zero balance with beaker, measure mass of liquid.
  • Measure volume with cylinder.
• Errors & Accuracy: Avoid water splashing, check zero error.

Insulation

• Objective: Determine best insulating material.
• Method:
  1. Wrap beakers in different materials or layers.
  2. Add hot water, measure temperature decrease over time.
• Graph: Bar graph or line graph of temperature decrease.
• Safety: Use funnel, keep beakers in center, use goggles.

General Safety and Accuracy Tips

• Use of goggles, avoid water spillage, disconnect circuits to prevent overheating.
• Address parallax error, maintain consistent conditions.

Conclusion

• These practicals cover essential concepts for physics exams.
• Encourage practice with past exam questions for better understanding.