Lesson 3 of 7 · Electricity
Experiment⭐ 30 XP⚡ Spark LabResistance and Ohm's Law
Electricity.
🎯 Your mission
Predict it first. Then prove yourself right (or wrong).
⚡ The twist
Energy never disappears — it just hides somewhere else.
Mind = Blown
⚡ Static electricity is the same physics as lightning, just smaller.
Make a hypothesis first
Before you start: which will move faster, and why?
What You'll Learn
Resistance is potential difference divided by current, R = V/I, in ohms. For a metallic conductor at constant temperature, current is proportional to potential difference — Ohm's law. Heat the wire and the line curves, because resistance rises with temperature.
Key Words
Tap a word to see its definition.
Materials Needed
- variable low-voltage supply
- fixed resistor
- filament lamp
- ammeter
- voltmeter
- graph paper
Safety First
- Keep currents small and switch off between readings to avoid overheating.
- Low-voltage supply only.
Steps
Read the explanation above and note the two key terms before you start.
Vary the supply to a fixed resistor and record current against potential difference for six settings. Plot V against I and take the gradient as resistance. Repeat with a filament lamp and compare the shapes.
Record what actually happened, including anything that did not match what you expected.
Write a conclusion that answers the question this lesson opened with, and state your uncertainty.
Check Your Understanding
Question 1
1 of 2A component carries 0.5 A under 6 V. Its resistance is:
Where you see this in real life
You use this every time you flip a light switch, ride a bike, or kick a ball.
Stretch Challenge
Try this in real life this week.
Time how long a small ball rolls down something, then change the slope and try again.
For the dinner table
“Show me something at home that uses this kind of energy.”
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Resistance and Ohm's Law
Predict it first. Then prove yourself right (or wrong).
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