Question

While tracing the path of a ray of light passing through a reactangular glass slab a student tabulated his observations. If in his experiment for two readings he takes two values of i as 40 º and 50º, what should be the correct values of e and r in each case ?

Answer 1

We know that for light the angle of incidence(i) should be equal to angle of emergence(e)

Hence angle of emergence (e) should also be 40° and 50° respectively.

For glass the refractive index is 1.5, hence

sin i/sin r = 1.5

=> sin r = sin i /1.5

a) For i= 40

Sin r = sin 40/1.5 = 0.64/1.5 = 0.428

=> r = sin⁻¹ 0.428 = 25.37°

b) for i = 50°

sin r = sin 50/1.5 = 0.766/1.5 = 0.51

=> r = sin⁻¹ 0.51 = 30.7°

Hence the value of r should be 25.37° and 30.7° respectively.

Answer 2

23,30 degree

Explanation:

correct answer according to marking scheme