Question

A ray is incident on a plane mirror. It's reflected ray is perpendicular to the incident ray. Find the angle of incidence

Answer 1

Answer:

45

Explanation:

Given : reflected ray is perpendicular to incident ray

That is to say , i+r=90

We know from the law of reflection that i=r ( angle of incidence = angle of reflection)

i+i=90

⇒2i=90

⇒i=r=45

Answer 2

Answer:

Given : reflected ray is perpendicular to incident ray

That is to say , i+r=99⁰

We know from the law of reflection that i = r ( angle of incidence = angle of reflection)

i + i = 90⁰=>2i = 90⁰

=>i + r = 45⁰