Why this practical matters
These experiments link current, potential difference, resistance, and energy in a clear lab circuit.
Keep the circuit closed only for short periods so the resistor does not overheat too much.
What You Need
Apparatus
- power supply or cells
- ammeter and voltmeter
- variable resistor
- resistor, wire, thermistor, or bulb
- resistor wire and thermometer
Key Formula
Say the formula out loud before you start the calculation. It helps students and examiners follow your logic.
How To Do It
- Set up the verification of joule's law apparatus neatly and make sure the scale or meter reading starts from a known point.
- Build the circuit neatly, check the meter polarity, vary one quantity at a time, and plot a graph where needed.
- Use the result to explain the physics idea in simple English. Keep the circuit closed only for short periods so the resistor does not overheat too much.
Simple Explanation
Keep the circuit closed only for short periods so the resistor does not overheat too much.
In the lab, we are not just collecting numbers. We are showing a physics rule in a real and reliable way. That is why careful setup, repeat readings, and clear labelling matter so much.
Common Mistakes
- Putting the voltmeter in series.
- Forgetting to switch off before changing the circuit.
- Using too high a current and heating the component too much.
Exam Tips
- Say which meter goes in series and which goes in parallel.
- Describe the graph shape, not only the readings.
- Mention why the circuit must be kept cool when needed.
- State the observation, the method, and the conclusion in that order.