Question

A ray of light is incident at an angle of 45degree at the interface of medium (1) air and medium 2 . If the angle of refraction is 30 degree , find the refractive index of medium (2) with respect to medium (1).
If the second medium is water in place of medium (2), will the angle of refractions increase or decrease ? Why

Answer 1

Step-by-step explanation:

Given : i=450   r=300  (μair)

To find : μwater

Solution: From snell's law

μ1sini=μ2sinr

μairsin450=μwsin300

21=2μw

μw2

Now let us take that for angle of incidence α the angle between reflected ray and refracted ray be 900 then

α+r+900=1800/900   (since i = angle of reflection from laws of reflection)

Hence r=90−α

Now from snell's law

μ1sinα=μ2sinr

1sinα=2sin(90−α)

tanα=2

α=tan−1