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प्रश्न
The speed of light in air is 3 × 108 ms-1. Calculate the speed of light in water. The refractive index of water is 4/3.
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उत्तर
The refractive index of water `="Speed of light in air"/"Speed of light in water"`
∴ Speed of light in water `="Speed of light in air"/"Refractive index of water"`
= `(3xx10^8)/(4//3)`
= 2.25 × 108 ms−1.
संबंधित प्रश्न
When rays of light are incident on a glass slab then the incident ray and emergent ray are _________ each other.
- perpendicular
- parallel
- opposite
- concurrent
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- and the angle of refraction (r).
Fill in the blanks to complete the following sentence
When light travels from a denser to a rarer medium, its speed ……………….
An object is viewed through a glass prism with its vertex pointing upwards. It appears to be displaced upward. Explain the reason.
In the fig., PO is a ray of light incident on a rectangular glass block.
(a) Complete the path of the ray through the block.
(b) In the diagram, mark the angle of incidence (i) and the angle of refraction (r) at the first interface. How is the refractive index of glass related to the angles I and r?
(c) Mark angle of emergence by the letter e. How are the angles i and e related?
(d) Which two rays are parallel to each other? Name them.
(e) Indicate in the diagram the lateral displacement between the emergent ray and the incident ray.
Fig shows a lens as a combination of a glass block and two prisms.
(i) Name the lens formed by the combination.
(ii) What is the line XX' called?
(iii) Complete the path of the incident ray PQ after passing through the lens.
(iv) The final emergent ray either meets XX' at a point or appears to come from a point on XX'. Label it as F, What is this point called?
