Lesson 3 of 6 · Light Optics
Experiment⭐ 30 XP⚡ Spark LabConverging and Diverging Lenses
Light Optics.
🎯 Your mission
Predict it first. Then prove yourself right (or wrong).
⚡ The twist
The opposite of what you expect is often what happens.
Mind = Blown
🔥 A bolt of lightning is 5 times hotter than the surface of the sun.
Make a hypothesis first
Predict: what happens if you double the force?
What You'll Learn
A convex lens brings parallel rays to a focus and can form a real, invertible image; a concave lens spreads them and always forms a virtual, upright, smaller one. Focal length sets the power: the shorter the focal length, the stronger the lens.
Key Words
Tap a word to see its definition.
Materials Needed
- convex lens
- concave lens
- lamp
- screen or card
- metre rule
- lens holder
Safety First
- Never use a lens to focus sunlight — it starts fires and can blind.
- The lamp gets hot; let it cool before moving it.
Steps
Read the explanation above and note the two key terms before you start.
Use a convex lens to project a window onto a card and measure the focal length. Then move a lamp from beyond 2f to inside f, recording at each stage whether the image is real or virtual, upright or inverted, larger or smaller.
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 concave lens always forms an image that 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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Converging and Diverging Lenses
Predict it first. Then prove yourself right (or wrong).
Full screen — no distractions
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