Light having a speed in vacuum of3.0�108m/s enters a liquid of refractive index 2.0. in this liquid, its speed will be a)0.75�108m/sb)6.0�108m/sc)1.5�108m /sd)3.0�108m/se)none of the above choices are correct.

Right

The Absolute Refractive index is the quotient of the speed of light in vacuum and the speed of light in the medium whose index is calculated , as shown in the expression below:

    (1)

This is a dimensionless value.

If we know that:

is the refractive index in vacuum

is the refractive index in the liquid

We can use equation (1), with the values of and to calculate , which is the velocity of light in this medium:

    (2)

    (3)

   (4)

Finally:

>>>>This is the speed of light in the liquid.

Therefore the correct option is c.  

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