Question

an object is placed 20cm in front of a concave mirror of focal length 15cm find the distance and nature of the image formed​

Answer 1

Answer:

Given :

object distance=-20cm  [ sign conventions]

Image distance=v=?

focal length=f=-15cm

Formula to be used:

1/f=1/u+1/v

1/v=1/f-1/u

=-1/15+1/20

= -4+3/60

=-1/60

v=-60 cm

hence object is placed between F and c and image formed is beyond C .

Nature of image:

-->Real  AND INVERTED

--->MAGNIFIED

--->AT A DISTANCE OF 60CM FROM THE MIRROR.

Object height=ho=3cm

Image height=?

magnification=m=-v/u

=60/-20

=-3

m=hi/ho

hi=mxho

=-3x3

=-9cm