Question

An object of size 5cm is kept at a distance of 25 cm from the optical centre of a converging lens of focal length 10m . Calculate the distance of the image from the lens & the size of the image .

Answer 1

if it is 10cms.

then

1/v - 1/u = 1/f

1/v - 1/(-25) = 1/10

1/v + 1/25 = 1/10

1/v = 1/10 - 1/25

1/v = 5-2/50

1/ v = 3/50

and v=16.6cm.

m= v/u
m= 16.6/
25

Answer 2

Answer:

if it is 10cm

then

1/v-1/u=1/f

1/v-1/(-25)=1/10

1/v+1/25=1/10

1/v=1/10-1/25

1/v=5-2/50

1/v=3/50

and v=16.6cm

m=v/u

m=16.6/25