A dentist uses a small concave mirror of focal length 3 cm and holds it at a distance of 2 cm from a tooth. Find out the magnification of the image formed.

Open in App

Solution

Given:
f = -3 cm; u = -2 cm; v = ?; m = ?
Using mirror formula,
1/v + 1/u = 1/f
1/v + 1/(-2) = 1/(-3)
1/v = 6
v = 6 cm
Using magnification formula:
m = -v/u
m = -6/(-2) = 3

Suggest Corrections

Similar questions

Q. A man holds a spherical shaving mirror of radius of curvature 60 cm, and focal length 30 cm, at a distance of 15 cm, from his nose. Find the position of image, and calculate the magnification.

Q. A dentist uses a small concave mirror of focal length 3 cm and hold it at a distance of 2 cm from the tooth. Which of the following statement is incorrect about the image formed?

A candle is placed at 60 cm from the pole of a concave mirror with focal length of 20 cm. Find the distance at which the image is formed and hence magnification.

A dentist uses a concave mirror of radius of curvature 3 cm and places an object at a distance of x cm from the mirror to get a magnification of +5 .Find x

Q. A dentist wants a small mirror that when placed

2

cm from a tooth, will produce

3 \times

upright image. What kind of mirror must be used and what must its focal length be?

Join BYJU'S Learning Program

A dentist uses a small concave mirror of focal length 3 cm and holds it at a distance of 2 cm from a tooth. Find out the magnification of the image formed.

Given: f = -3 cm; u = -2 cm; v = ?; m = ? Using mirror formula, 1/v + 1/u = 1/f 1/v + 1/(-2) = 1/(-3) 1/v = 6 v = 6 cm Using magnification formula: m = -v/u m = -6/(-2) = 3

Given:
f = -3 cm; u = -2 cm; v = ?; m = ?
Using mirror formula,
1/v + 1/u = 1/f
1/v + 1/(-2) = 1/(-3)
1/v = 6
v = 6 cm
Using magnification formula:
m = -v/u
m = -6/(-2) = 3