Class 12 Physics - Chapter Ray Optics And Optical Instruments NCERT Solutions | A small candle, 2.5 cm in size is placed

Welcome to the NCERT Solutions for Class 12th Physics - Chapter Ray Optics And Optical Instruments. This page offers a step-by-step solution to the specific question from Exercise 1, Question 1: a small candle 2 5 cm in size is placed at 27 cm....
Question 1

A small candle, 2.5 cm in size is placed at 27 cm in front of a concave mirror of radius of curvature 36 cm. At what distance from the mirror should a screen be placed in order to obtain a sharp image? Describe the nature and size of the image. If the candle is moved closer to the mirror, how would the screen have to be moved?

Answer

Size of the candle, h = 2.5 cm

Image size = h’

Object distance, u = −27 cm

Radius of curvature of the concave mirror, R = −36 cm

Focal length of the concave mirror, f = R/2 = -18 cm

Image distance = v

The image distance can be obtained using the mirror formula:

Therefore, the screen should be placed 54 cm away from the mirror to obtain a sharp image.

The magnification of the image is given as:

The height of the candle’s image is 5 cm. The negative sign indicates that the image is inverted and virtual.

If the candle is moved closer to the mirror, then the screen will have to be moved away from the mirror in order to obtain the image.

Popular Questions of Class 12 Physics

Recently Viewed Questions of Class 12 Physics

4 Comment(s) on this Question

Write a Comment: