Question

The teacher asks a student to fix the given screen at an appropriate place in the given experimental set up, so that a clear image can be obtained on the screen. If the focal length of convex lens in 8 cm, find the mark on the scale at which he should fix up the screen?

Answer 1

When the object is at infinity from a convex lens, then the image formed is at focus (on the other side of the lens). The lens with stand is fixed at 5.8cm. The focal length of convex lens is 8 cm. Therefore, he should fix up the screen at 13.8 cm mark on the scale.