Question

A dentist uses a mirror in front of a decayed tooth at a distance of 4 cm from the tooth to get a four time magnified errect image in the mirror. Use mirror formula to find focal length and nature if mirror used

Answer 1

Heyaaa!!!! Here is your brainliest Answer....

object distance, u = -4 cm

magnification, m= 4

we know, m = -v/u ⇒ v = -mu ⇒ v = -(4)(-4) = 16 cm

so image distance= 16 cm

now, by mirror formula ,

   1/v + 1/u = 1/f

⇒ 1/16 + 1/-4 = 1/f

⇒ (1-4)/16 = 1/f

⇒ 1/f = -3/16

∴ focal length = -5.33 cm

only a concave mirror can form magnified images.

since the image is formed behind the mirror, it is virtual and erect

Hope this will help you...

Rate this answer

Dont forget to thank me..

Have a good day