An object is placed 30cm from a concave mirror of focal length 15cm.?

Question

The linear magnification of the image produced is

Answer 1

To calculate magnification of the image using mirror formulae,

m = I/O

    = – v/u

    = f/f–u 

Here f is focal length,u is the distance of object from concave mirror.

Substitute 15 cm for f and 30 cm for u in above formulae,

m= 15/15-30

   =-2

Magnification of the image is -2

Comments

Linear magnification m = 15/(15-30)

= 15/-15

= -1

A negative sign in the value of the magnification indicates that the image is real.

Magnification of the image is 1 cm.