Question

In an equilateral glass prism for two angle of incidence differing by 10^o the angle of deviation is found to be 40^o find these angles of incidence.

Answer 1

Answer: 45° and 55°

Explanation:

For a prism, the angle of deviation is given by:

δ=i₁+i₂-A

where A is the angle of prism.

A=60° (equilateral prism)

Angle of deviation, δ=40°  (given)

i₁, i₂ are the angles of incidences

i₁-i₂=10°⇒i₁=10°+i₂

i₁+i₂=δ+A

⇒i₁+i₂=40°+60°= 100°

Substitute the value of i₁

10°+i₂+ i₂= 100°⇒2 i₂=90°⇒i₂=45°

i₁=100-45°=55°