Question

Find the refractive index of air with respect to water (n water= 4/3).

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Answer 1

Given ;

Refractive index of water = 4/3

To Find ;

Refractive index of air wrt water

Concept ;

☞ Refractive index of medium is defined as ratio of velocity of light in vaccum to the velocity of light in medium.

☞ Refractive index is an unitless as well as dimensionless quantity.

☞ Refractive index of medium A wrt medium B is given by

$\boxed{\bf{\purple{\eta_{AB}=\dfrac{\eta_A}{\eta_B}}}}$

✳ Refractive index of air = 1

Calculation ;

$\implies\sf\:\eta_{aw}=\dfrac{\eta_a}{\eta_w}\\ \\ \implies\sf\:\eta_{aw}=\dfrac{1}{1.33}\\ \\ \implies\boxed{\bf{\pink{\eta_{aw}=0.75}}}$