Question

Find the value of the angle of reflection when a indicident ray makes and angle 40 with a plane minor. ​

Answer 1

Answer:

$\rm 50^\circ$

Explanation:

As per the provided information in the given question, we have :

• An incident ray makes and angle 40° with a plane mirror.

We are asked to calculate the measure of angle of reflection.

According to the question, measure of the angle between the plane mirror and the incident ray is 40°. As per the figure,

• ∠AOD = 40°

Here, OC is the the normal which perpendicular to the point of incidence. Measure of the angle of perpendicular is always 90° as it is making a right angle. So,

⇒ ∠AOC = ∠AOD + ∠DOC

⇒ 90° = 40° + ∠DOC

⇒ 90° - 40° = ∠DOC

⇒ 50° = ∠DOC

⇒ 50° = Angle of incidence

Henceforth, the measure of the angle of incidence is 50°.

Now, according to the second law of reflection,

• Angle of reflection and angle of incidence are have always equal measurements

⇒ ∠i = ∠r

⇒ ∠DOC = ∠BOC

⇒ 50° = ∠BOC

⇒ 50° = Angle of reflection

∴ The measure of the angle of reflection is 50°.