velocity of light in medium1 and medium2 are v1 and v2 respectively
1)what is the relative refractive index of medium2 with respect to medium 1 in terms of velocity of light
2) what is the refractive index of medium1 with respect to medium2 in terms of velocity of light
Answers
1) Refractive index of a medium = Speed of light in vacuum/Speed of light in that medium
The refractive index of medium 2 with respect to medium 1 is given by the ratio of the speed of light in medium 1 and the speed of light in medium 2.
Refractive index of medium 2 with respect to medium 1=Speed of light in medium 1/Speed of light i medium 2.
2) Refractive index of medium 1 with respect to medium 2 is velocity of light in medium 2 divided by velocity of light in medium 1.
The phenomenon of change of velocity of light at the interface between two media is called refraction.
n12=v2/v1=(Lambda2)/(Lambda1)=sin i/sin r.
Here f is frequency of light which remains constant due to law of conservation of energy. Here, i is angle of incidence formed at interface in medium 2 and r is angle of refraction in madium 1.
According to Snell’s law n2sin i=n1 sin r. Therefore sin i/sin r=n1/n2 or n12=ni/n2. Here, n1 and n2 are absolute refractive indices of medium 1 and 2. Absolute refractive index means refractive index w.r.t. air or vacuum.