Question

1. If the angle between two inclined plane mirrors is 5. Find the number of images formed?
2. If the sum of angles of incidence and reflection is 160º, what is the - a) Angle of incidence. b)
Angle between incident ray and the reflecting mirror surface.​

Answer 1

Answer:

2.a.angle of incidence is 80 degree

Answer 2

The number of images formed is 71 and angle of incidence is 80° and Angle between incident ray and the reflecting mirror surface is 10°.

• According to formula no of images case(m) =360/angle b/w mirrors

• So, here 360/5 =72
• If m is even than the no. of images is always m-1
• So, correct answer is 72-1= 71

• The law of reflection states that the incident ray, the reflected ray, and the normal to the surface of the mirror all lie in the same plane. Furthermore, the angle of reflection is equal to the angle of incidence. . Both angles are measured with respect to the normal to the mirror.
• So, angle of incidence+angle of reflection = 160°

∴ angle of incidence = 160°/2 = 80 ° [as angle of incidence=angle of reflection]

• angle between mirror surface and imaginary plane is 90°

∴So, Angle between incident ray and the reflecting mirror surface is 90° - angle of incidence = 90° - 80° = 10°