﻿ A thin flat glass plate is placed in front of a convex mirror. At what distance b from the plate should a point source of light S be placed so that its image produced by the rays reflected from the front surface of the plate coincides with the image formed by the rays reflected from the mirror? The focal length of the mirror is f = 20 cm and the distance from the plate to the mirror a = 5 cm. How can the coincidence of the images be established by direct observation                                                                                                                                       : Kaysons Education

# A Thin Flat Glass Plate Is Placed In Front Of A Convex Mirror. At What Distance B From The Plate Should A Point Source Of Light S Be Placed So That Its Image Produced By The Rays Reflected From The Front Surface Of The Plate Coincides With The Image Formed By The Rays Reflected From The Mirror? The Focal Length Of The Mirror Is F = 20 Cm And The Distance From The Plate To The Mirror A = 5 Cm. How Can The Coincidence Of The Images Be Established By Direct Observation

#### Video lectures

Access over 500+ hours of video lectures 24*7, covering complete syllabus for JEE preparation.

#### Online Support

Practice over 30000+ questions starting from basic level to JEE advance level.

#### National Mock Tests

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

#### Organized Learning

Proper planning to complete syllabus is the key to get a decent rank in JEE.

#### Test Series/Daily assignments

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

## Question

### Solution

Correct option is

15 cm

mage formed by plane mirror = (– 15) cm

Object distance from mirror = (b + 5) cm

Now,

1/v  + 1/u =1/f

b = 15 cm.

#### SIMILAR QUESTIONS

Q1

A ray of light falls on a plane mirror. When the mirror is turned, about an axis at right angle to the plane of the mirror through 20o, the angle between the incident ray and new reflected ray is 45o. The angle between the incident ray and original reflected ray is

Q2

A fluorescent lamp of length 1 m is placed horizontal at a depth of 1.2 m below a ceiling. A plane mirror of length 0.6 m is placed below the lamp parallel to and symmetric to the lamp at a distance 2.4 m from it. The length of the reflected patch of light on the ceiling is

Q3

Two plane mirrors are placed parallel to each other. A point object is placed between them. The distance of image formed in one of the mirror is in

Q4

Two plane mirrors are parallel to each other and spaced 20 cm apart. A luminous point object is placed between them and 5 cm from one mirror. What are the distances from each mirror of the three nearest images in each?

Q5

If two adjacent walls and the ceiling of a rectangular room are mirror surfaced, then how many images of himself, a man can see?

Q6

Two bodies A and B are moving towards a plane with speeds VA and VB respectively as shown in figure. The speed of image of A with respect to the body B is

Q7

A beam of convergent light converges to a point 0.5 in front of the mirror after reflection at a convex mirror but in the absence of the mirror the beam converges to a point 0.2 behind the mirror. The radius of curvature of the mirrors is

Q8

A particle executes SHM in front of a concave mirror of radius 1 m, about the centre of curvature, with very small amplitude a. The amplitude of oscillation of the image is

Q9

A particle moves towards a concave mirror of focal length 30 cm along its axis and with a constant speed of 4 cm/ sec. What is the speed of its image when the particle is at 90 cm from the mirror?

Q10

A screen S is placed a distance b = 5 cm from a circular convex mirror as shown in figure. An object RP of height h = 3 cm is arranged a distance a = 5 cm from the screen. Where must an observer position himself to see the image of the entire object? What are the maximum dimensions of the object (with the given arrangement of the object, the mirror and the screen) for the mirror to reproduce and image of the entire object? The diameter of the mirror is d = 10cm.