Question

9,) The diagram in shows an incident ray
AO and the reflected ray OB from a plane mirror.
The angle AOB is 30°. Draw normal on the plane
mirror at the point O and find :
(a) the angle of incidence
(b) the angle of reflection
B
А

30°​

Answer 1

Answer:

(i) the angle of incidence

(ii) the angle of reflection

ON is normal on the plane mirror at point O

ON is perpendicular on a plane mirror

Angle of incidence ∠i=∠AON

and angle of reflection ∠r=∠BON

Since, ∠i−∠r

∠AOB=30

0

⇒ ∠AON+∠BON=30

0

⇒ ∠i+∠i=30

0

⇒ 2∠i=30

0

⇒ ∠i=30/2=15

0

∴ Angle of incidence = ∠i=15

0

and Angle of reflection = ∠r=15

0