Question

Practice Problems :
1. A ray of light strikes a glass slab of refractive index 1.5 at an angle of 37°. What is
the angle of refraction?
[24°]​

Answer 1

Answer:

According to snell's law we know that the ratio of sine of angle of incidence to the sine of angle of refraction is a constant for a given pair of medium.

i.e.

begin mathsize 14px style fraction numerator sin space straight i over denominator sin space straight r end fraction equals straight mu space where space straight mu space is space the space refractive space index space of space the space second space medium space with space respect space to space the space first space medium. end style

 

Given that i = 37°, μ =1.5  

begin mathsize 14px style fraction numerator sin space 37 degree over denominator sin space straight r end fraction equals 1.5 sin space straight r space equals fraction numerator sin space 37 degree over denominator 1.5 end fraction sin space straight r space equals fraction numerator 0.602 over denominator 1.5 end fraction straight r space equals sin to the power of minus 1 end exponent space 0.401 straight r space approximately equal to space 24 degree end style

 

Or in other words we can write snells law as:

begin mathsize 14px style fraction numerator sin space straight i over denominator sin space straight r end fraction equals straight n subscript 2 over straight n subscript 1 where space straight n subscript 2 space is space the space refractive space index space of space the space second space medium left parenthesis glass space slab right parenthesis space and space straight n subscript 1 space the space refractive space index space of space first space medium left parenthesis air right parenthesis. fraction numerator sin space 37 degree over denominator sin space straight r end fraction equals fraction numerator 1.5 over denominator 1 end fraction taking space straight n subscript 1 space equals 1 rightwards double arrow sin space straight r space equals fraction numerator sin space 37 degree over denominator 1.5 end fraction sin space straight r space equals fraction numerator 0.602 over denominator 1.5 end fraction sin space straight r space equals 0.401 straight r space equals sin to the power of minus 1 end exponent space 0.401 straight r space approximately equal to space 24 degree end style

Answered

Explanation: