A beam of light is supposed to be deviated through 60 degrees by a plane mirror, what must be the angle between the mirror and the direction of the incident ray.
Answers
Explanation:
As shown in the figure ,when the incident ray deviates by 60° after refraction means reflected angle makes an angle 30° with the mirror and the other 30°is made with the undeviated light behind the mirror.
As seen from the figure ,but symmetry and due to law of refraction ( angle of incidence is equals to angle of reflection).incident angle makes an angle 30° with the mirror.
angle of incidence=angle of reflection =60°.
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We know, a reflected ray and an incident ray make an angle of 90° with the normal. According to the given conditions, a beam has to deviate through 60° by a plane mirror.
◘ Angle of reflection = 60° = angle of incidence
Now,
The angle made with the mirror would be :- 90° - 60° = 30°
Therefore, the angle between the mirror and the direction of the incidence must be 30°.
(Refer to the attachment ↑)
