Question

Which of the following ray diagrams is correct for
the ray of light incident on a concave mirror as shown
in figure?​

Answer 1

Answer:

first ray is correct because it will get deflected

Answer 2

The ray diagram shown in the attachment is correct.

Explanation:

When a ray is incident parallel to principle axis it means that the object is at infinite distance from the Pole of the mirror.

The ray passes through focus(F) of the concave mirror.

Mirror formula is:         $\frac{1}{U}$ + $\frac{1}{V}$ =  $\frac{1}{f}$

Here, U = distance of object from pole.

         V = distance of image from pole.

          f = focal length of mirror

By convention let us take distances to the left of pole as negative and those to the right of pole as positive.

∴ In the given formula   f = (-f)

                                      U = - ∞ and V is unknown.

∴ $\frac{1}{(-f)}$ = $\frac{1}{V}$ +  $\frac{1}{(-infinite)}$

∴ V = -f

∴ Image is formed at a distance of 'f' from the pole of the mirror to the left of the pole.

∴ The ray intersects the principle axis at the focus.