When an object of height 3 cm is placed at a distance of 30 cm from a lens, a real image is formed at a distance of 60 cm. Find out the height of the image?
-6 cm
Here, u=-30 cm, v=+60 cm, ho=3 cm, hi=?
Using, magnification, m=(vu)=+60−30=−2
Also, magnification, m=hiho=hi3
Now, −2=hi3
⇒hi=−6 cm
The negative sign shows that the image is real and inverted.