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ExamsLogic Revision Series | Independent study guide based on the official curriculum.
Electricity Practical

I-V Characteristics of Different Components

Leaving Cert Physics Practical Notes

These experiments link current, potential difference, resistance, and energy in a clear lab circuit. This page is written in simple English so students can understand the experiment, the result, and the reason behind it.

LevelHigher and Ordinary
FocusCircuit graphs practical
Exam memory lineDescribe the shape of each graph and why the shape changes.
LevelHigher and Ordinary
AreaElectricity
Main ideaI-V Characteristics of Different Components
What to say in classDescribe the shape of each graph and why the shape changes.
ohmic graphbulb/diode graph
Premium practical diagram for i-v characteristics of different components.

Why this practical matters

These experiments link current, potential difference, resistance, and energy in a clear lab circuit.

Describe the shape of each graph and why the shape changes.

What You Need

Apparatus

  • power supply or cells
  • ammeter and voltmeter
  • variable resistor
  • resistor, wire, thermistor, or bulb
  • metallic conductor, bulb, diode, and copper sulfate cell

Key Formula

I = V / R for an ohmic component

Say the formula out loud before you start the calculation. It helps students and examiners follow your logic.

How To Do It

  1. Set up the i-v characteristics of different components apparatus neatly and make sure the scale or meter reading starts from a known point.
  2. Build the circuit neatly, check the meter polarity, vary one quantity at a time, and plot a graph where needed.
  3. Use the result to explain the physics idea in simple English. Describe the shape of each graph and why the shape changes.

Simple Explanation

Describe the shape of each graph and why the shape changes.

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.

Simulator / Quick Check

I-V Characteristics of Different Components simulator
Enter values and press Run.