Question

Two plane mirrors are placed at right angles to each other. A ray strikes one mirror at an angle of incidence θ such that it is also reflected from the second mirror. Then, the ray reflected from the second mirror will be 

Solution

Correct option is

Parallel to that incident on the first mirror

The incident ray AB strikes the first mirror M1 at an angle θ and is reflected along BC, as shown in fig (a). The ray BC is incident on mirror M2 at an angle α = 90o – θ and is reflected along CD making an angle  with the mirror M2. It is clear from fig (b) that the ray CD is parallel to the ray AB but its direction is reserved.

SIMILAR QUESTIONS

Q1

What is the SI unit of luminous intensity?

Q2

What are the dimensions of luminous intensity?   

Q3

What is the luminous intensity of a lamp which produces an illuminance of 12 lux at a distance of 5.0 m from it?  

Q4

To print a photograph from a negative, the time of exposure to light from a lamp placed 60  cm away is 2.5 s. What exposure time is required if the lamp is placed 1.2 m away?

Q5

A lamp placed at a distance of 50.0 cm from a screen on one side produces the same illumination as a standard 60 cd candle placed 100 cm away on the other side of the screen. What is the luminous intensity of the lamp?

 

Q6

An observer moves towards a stationary plane mirror at a speed of 4 ms–1. With what speed will his image move towards him?  

Q7

Which mirror should be used to obtain a parallel beam of light from a small lamp?

Q8

Choose the only wrong statement from the following.

Q9

A short linear object of length L lies on the axis of a spherical mirror of focal length f at a distance u from the mirror. Its image has an axial lengthL’ equal to

Q10

Two plane mirrors are inclined to each other at an angle of 70o. A ray is incident on one mirror at an angle θ. The ray reflected from this mirror falls on the second mirror from where it is reflected parallel to the first mirror. What is the value of θ?