Grade 12Wave Optics

A ray of light makes an angle of 10° with the horizontal above it and strikes a plane mirror which is inclined at an angle O to the horizontal. The angle O for which the reflected ray becomes vertical is
(a) 40°. (B)50°. (C)80°. (D) 100°

Sarthak jain

11 Years agoGrade 12

3 Answers

Abhishek Kumar

11 Years ago

Draw a ray-diagram,
Angle between the reflected and incident ray = 80 (Final ray is vertical and incidence is 10 wrt horizontal)
Angle of incidence = angle of reflected ray = 40
Angle of reflected ray with mirror = 90 – 40 = 50
So, angle with horizontal = 90 – 50 = 40

SAKSHI

7 Years ago

A ray of light makes an angle of 10° with the horizontal above it and strikes a plane mirror which is inclined at an angle O to the horizontal. The angle O for which the reflected ray becomes vertical is

Kushagra Madhukar

6 Years ago

Dear student,

Please find the attached solution to your question.

Angle between the reflected and incident ray = 80 (Final ray is vertical and incidence is 10 wrt horizontal)
Angle of incidence(i) = angle of reflection(r) = 40
Angle of reflected ray made with mirror = 90 – 40 = 50
So, angle with horizontal = 90 – 50 = 40⁰

Hope it helps.

Thanks and regards,

Kushagra