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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 whether light slows down or speeds up in the following cases :
Light going from air to glass.
When light travels from a denser to a rarer medium, its speed ______.
A light ray suffers reflection and refraction at the boundary in passing from air to water. Draw a neat labelled ray diagram to show it.
Compare the speeds of light of wavelength 4000 Å (i.e. violet light) and 8000 Å (i.e. red light) in vacuum.
Light travels ______ kilometers per second in air or vacuum. In theory, nothing can travel faster than light.
Materials that allow light to pass through completely are known as ______ material.
Define opaque material.
Light is one of the slowest traveling energy with a speed of 3 × 10-8ms-1
Higher-Order Thinking Skills:
M = 2.42 for diamond. What is the meaning of this statement in relation to the speed of light?
Light travels a distance of '10x' units in time 't1' in vacuum and it travels a distance of 'x' units in time 't2' in a denser medium. Using this information answer the question that follows:
'Light covers a distance of '20x' units in time 't1' in diamond'. State true or false.
