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प्रश्न
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उत्तर
According to the principle of reversibility, the path of a light ray is reversible.
For e.g. if light travels from air to water along a certain path, then if the path is reversed while travelling from water to air, it will follow exactly the same path.
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संबंधित प्रश्न
When a ray of light from air enters a denser medium, it ______.
How does the angle of deviation produced by a prism change with increase in the angle of incidence. Draw a curve showing the variation in the angle of deviation with the angle of incidence at a prism surface.
In fig 4.18, name the ray which represents the correct path of light while emerging out through a glass block.
The refractive index of air with respect to glass is expressed as `""_g μ_a=sin i /sin r`.
- Write down a similar expression for aμg in terms of the angles i and r.
- If angle r = 90°, what is the corresponding angle i called?
- What is the physical significance of the angle i in part (b)?
A ray of light enters a glass slab ABDC as shown in figure and strikes at the centre O of the circular part AC of the slab. The critical angle of glass is 42°. Complete the path of the ray till it emerges out from the slab. Mark the angles in the diagram wherever necessary.
A ray of light OP passes through a right angles prism as shown in the adjacent diagram.
(a) State the angles of incidence at the faces AC and BC.
(b) Name the phenomenon which the ray suffers at the face AC.
Does the depth of a tank of water appear to change or remain the same when viewed normally from above?
What is the total reflecting prism?
How does the angle of deviation produced by a prism depend on the colour of light used? Which colour of white light is deviated (i) most, (ii) least, by a prism?
The diagram below shows two parallel rays A (Orange) & B (Blue) incident from air, on air-glass boundary.
- Copy and complete the path of the rays A and B.
- How do the speeds of these rays differ in glass?
- Are the two refracted rays in glass parallel? Give a reason.
