Same chapter3 marksDifficulty: Medium
State two properties of ultraviolet radiation and one of its harmful effects.
Spectrum
3 marksDifficulty: Medium
Why does a rainbow form after rain?
Original Khojo Papers practice question — not from a past board paper.
Answer
Sunlight entering a raindrop is refracted and dispersed into its colours, then totally internally reflected at the back of the drop, and refracted again as it leaves. Because each colour emerges at a slightly different angle, an observer with the sun behind sees the colours spread out as an arc.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The primary rainbow has red on the outside and violet on the inside.
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Name the radiation that lies just beyond the red end of the visible spectrum and state one of its uses.
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