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प्रश्न
What is the speed of light in vacuum?
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उत्तर
The speed of light in vacuum is known to be almost exactly 300,000 km per second. In 1665 the Danish astronomer Ole Roemer first estimated the speed of light by observing one of the twelve moons of the planet Jupiter.
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संबंधित प्रश्न
State the speed of light in (a) air, (b) glass.
State whether light slows down or speeds up in the following cases :
Light going from glass to water.
The speed of light in air is 3 × 108 m s-1. Calculate the speed of light in glass. The refractive index of glass is 1.5.
An obliquely incident light ray bends at the surface due to a change in speed when passing from one medium to another. The ray does not bend when it is incident normally. Will the ray have a different speed in the other medium?
Compare the speeds of light of wavelength 4000 Å (i.e. violet light) and 8000 Å (i.e. red light) in vacuum.
The speed of light is maximum in ______.
Materials that are not able to allow light to pass through, are called ______ material.
Materials that allow light to pass through completely are known as transparent materials.
Define transparent materials.
Higher-Order Thinking Skills:
M = 2.42 for diamond. What is the meaning of this statement in relation to the speed of light?
