Question

What % of speed of light in air as compare to speed of light in vaccum

Answer 1

Dear Student, the refractive index in air is only 1.0003, so the speed of light in air is almost as fast as in vacuum.

Let v be the speed of light in air and c be the speed of light in vacuum and let n be the refractive index of air which is 1.0003. Then the percentage is given as

(v/c) x 100 = (1/1.0003) x 100​​​ = 99.7 %

So speed of light in air is 99.7% of that in vacuum.

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