Light

Looking Around 2 — Sense Organs. Eyes need light to see — transparent, translucent, and opaque objects are explored in Sense Organs.

• Light helps us see.
• Natural light (Sun) and artificial (bulb, torch).
• Opaque objects block light; transparent let it through.

Verbal: We see when light from an object reaches our eyes. Opaque blocks light; transparent lets it through.

Symbolic: Opaque → shadow. Transparent → clear view. Moon light = reflected sunlight (not its own).

Level 1 — We need light to see

Dark room → can't see objects until you switch on light.

Level 1 — Sources

Sun (day), moon reflects sun (night, dim), bulb, diya, torch.

Level 1 — Materials

Level 2 — Shadows (link)

Opaque object blocks light → shadow behind.

Level 2 — India

Diya at Diwali; studying under tube-light during power cut with torch.

Why can't you see your textbook in a completely dark room?

Step 1 — Eyes need **light** from object to reach them.
Step 2 — Dark room → no light from book.
Step 3 — Nothing to see without a light source.
Answer: No light reaches your eyes.

• Name a transparent object.
• Torch or sun — which is artificial light?
• What forms behind a book in sunlight?

Stretch: Classify at home: glass window, wooden door, frosted bathroom glass — transparent, translucent, or opaque?

Revision tip: Stand in sunlight with a book — watch your shadow and say which material blocked the light.

Open the Practice tab for graded questions on Light.