Question

11. State the laws of refraction of light. Explain the term 'absolute refraction index of a medium' and write an
expression to relate it with the speed of light in vacuum.
OR​

Answer 1

Answer:when light passes from rarer to denser medium it bend towards normal and velocity of light also decreases but frequency remains same

.

Sini/sinr = constant = n21(refractive index)

Where,

n21=n2/n1

Therefore sini/sinr=n2/n1

Hence n1×sini=n2×sinr(this is called as Snell's law)

By this equation we can find unknown refractive index of medium-2(n2).

Take n1=1 (for air)

And I=incident angle and

r=refractive angle

.

.

When light passes from vaccum to denser medium then such phenomena called as absolute refractive index

It's expression is

Absolute velocity of light in vaccum

refractive = -----------------------------------

index velocity of light in medium

snell's law is also derived by this absolute refractive index concept

n1=c/v1 and n2=c/v2

Now n21=v1/v2

Therefore n21=c/n1×n2/c (c gets cut)

n21=n2/n1

Hence derived......

I think this may help you

Explanation: