When a ray of light is incident on the first plane mirror and is parallel to the second mirror, the angle of incidence on the first mirror will be equal to the angle of reflection. This is a fundamental law of reflection.
In this case, since the two mirrors are inclined to each other at an angle of 60 degrees, the angle of incidence on the first mirror will also be 60 degrees. Since the ray is parallel to the second mirror, the angle of reflection will also be 60 degrees.
Now, let's consider the options:
A. Perpendicular to the first mirror: This cannot be true because we know the ray of light is parallel to the second mirror and the angle of reflection is equal to the angle of incidence, which is 60 degrees.
B. Parallel to the first mirror: This is true. The ray of light will be reflected back parallel to the first mirror, making an angle of 60 degrees with the incident ray.
C. Parallel to the second mirror: This cannot be true. The ray of light is parallel to the second mirror before reflection, but after reflection, it changes direction and will no longer be parallel to the second mirror.
D. Perpendicular to the second mirror: This cannot be true either. The ray of light is parallel to the second mirror before reflection and remains parallel to the first mirror after reflection, so it will not be perpendicular to the second mirror.
So, the correct answer is B. The ray of light will be reflected parallel to the first mirror.
