Question 23
EasyOriginal questionA pencil standing in a glass of water appears bent at the water's surface. This happens because of
Show the answer and explanation
Correct answer: B
Explanation
Light travels at different speeds in air and in water, so it changes direction as it crosses the boundary between them. That bending is refraction.
The light from the submerged part of the pencil reaches the eye along a bent path, and the eye reads it as coming from a shifted position.
Reflection would bounce the light back, dispersion splits white light into colours, and diffraction is the spreading of light around an obstacle.
Worth noting
The same effect makes a pool look shallower than it is, and for the same reason: the light from the bottom bends on the way out.
- Concept
- Refraction at a boundary between two media
- Typical timeTypical
- 45 s
- Your timeYours
- —
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