Which among the following can produce a parallel light beam when light is incident from a point source onto it?
Which among the following can produce a parallel light beam when light is incident from a point source onto it?
The correct option is D 1 & 3
As you can see in the figure, we have two mirrors and two lenses.
The first one is a concave mirror.
Rays passing through the focus, after reflection, go parallel to the principal axis.
Therefore, we will get a parallel beam of rays in the first case.
Next we have a convex mirror.
Rays passing through the focus, diverge after reflection and appear to converge behind the mirror.
Therefore we will not get parallel rays in the second case.
Next we have convex and concave mirrors, about which we will study in detail in this session.
As you can see in the third case, we have a convex lens.
Just like the first case, the rays passing through the focus go parallel after refraction.
As you can see in the figure, we have two mirrors and two lenses.
The first one is a concave mirror.
Rays passing through the focus, after reflection, go parallel to the principal axis.
Therefore, we will get a parallel beam of rays in the first case.
Next we have a convex mirror.
Rays passing through the focus, diverge after reflection and appear to converge behind the mirror.
Therefore we will not get parallel rays in the second case.
Next we have convex and concave mirrors, about which we will study in detail in this session.
As you can see in the third case, we have a convex lens.
Just like the first case, the rays passing through the focus go parallel after refraction.
