Refractive index of diamond with respect to glass is 1.6 and absolute refractive index of glass is 1.5. Find out the absolute refractive index of diamond.
Absolute refractive index of a medium shows the ratio of speed of light in air to speed of light in that medium. Let us assume c is the speed of light in air, v1 is speed of light in glass and v2 is speed of light in diamond.
ndg = v1/ v2 = 1.6
Absolute refractive index of glass
= − =1.5
or,
v1 = c / 1.5
Substituting the value of v1 in equation (1) we get;
c / 1.5 v = 1.6
c / v2 = 1.6 x 1.5
=2.4
So, absolute refractive index of diamond=2.4