A 4.5 cm needle is placed 12 cm away from a convex mirror of focal length 15 cm. Give the location of the image and the magnification. Describe what happens as the needle is moved farther from the mirror.

Open in App

Solution

Height of the needle, h₁ = 4.5 cm

Object distance, u = −12 cm

Focal length of the convex mirror, f = 15 cm

Image distance = v

The value of v can be obtained using the mirror formula:

Hence, the image of the needle is 6.7 cm away from the mirror. Also, it is on the other side of the mirror.

The image size is given by the magnification formula:

Hence, magnification of the image,

The height of the image is 2.5 cm. The positive sign indicates that the image is erect, virtual, and diminished.

If the needle is moved farther from the mirror, the image will also move away from the mirror, and the size of the image will reduce gradually.

Suggest Corrections

Similar questions

A 4.5 CM needle is placed 12 centimetre away from a convex mirror of focal length 15 CM give the location of the image and magnification describe what happens to the needle as the needle is moved farther from the mirror

Q. 4.5 cm needle is placed 12 cm away from a convex mirror of focal length 15 cm. Give the location of the image and the magnification.

Q. A

1 c m

height needle is placed at a distance of

0.1 m

from a convex mirror of focal length

0.05 m

, then size of the image is

(a) An object is placed just outside the principal focus of concave mirror. Draw a ray diagram to show how the image is formed, and describe its size, position and nature. (b) If the object is moved further away from the mirror, what changes are there in the position and size of the image ? (c) An object is 24 cm away from a concave mirror and its image is 16 cm from the mirror. Find the focal length and radius of curvature of the mirror, and the magnification of the image.

Join BYJU'S Learning Program