Question

an object of height 4cm is placed at a distance of 15 cm in front of a concave lens of power 10d . Find the size if the image​

Answer 1

Given- height of object (h1)=4cm

Distance of object (u)=15cm

Power= 10D

To find= h2

Solution= for focal length

P=1/f

Therefore, f= 1/10D =0.1m= 10cm

1/v=1/f+1/u

I/v = 1/-10 +1/15

1/10 - 1/15

1×3/10×3 - 1×2/15×2

3/30 - 2/30

3-2/30

1/30

Position of image is 1/30

By magnification formula you can find size of image

That is h2/h1 =v/u

H2/4 =1/30/15

H2= 4×15/30

H2= 2cm