Question

The diagram below shows a light source P in bad that in a rectangular glass block ABCD of critical angle 42 degree complete the path of ray PQ is out of the block
writing angles

Answer 1

Given: Critical angle 42 degree.

To find: Complete the path of ray PQ, also find the angle.

Solution:

• Now, lets consider a glass slab ABCD. As given in the question that the light source P is embedded in a rectangular glass block ABCD having critical angle as 42°.

• Now, let the refracted ray meets at B on the side CD of the glass prism ABCD.

• So, at A, angle of incidence is 38°

              38° >  i(c)

• So, Total Indicator Reading is acting.

• So, anlge ABC = 42°

              angle of refraction is 90°.

Answer:

      So, on CD, the ray PA will beet at B, with the angle 42° and angle of refraction is 90°.