Question

A parallel beam of light falls on a converging lens. Which diagram shows what happens to the beam of light?

Answer 1

Explanation:

the rays all converge at focus , i.e, at 20cm from lens (10cm from screen)

now the length of side be s

ratio of sides =ratio of distance of focus from lens to the distance of focus

from screen

s

1

=

10

20

s=0.5cm, and the image is inverted, hence option D is correct

Answer 2

The answer is as follows:

Explanation:

• Light rays enter a convex lens parallel to the horizontal axis and converge at a single spot on the other side.

• Convergent light rays change direction and collide at a point called focus.
• and the ray travelling through the focus reflects as parallel to the major axis.

• A concave mirror's parallel rays will converge at the focal point in front of the mirror.
• Parallel rays rebounding off a convex mirror, on the other hand, will diverge away from the focal point (behind lens).