Which of the following is correct for the reflected ray if a light ray strikes a plane mirror at an angle of 50° from the normal?
40° from the surface of the mirror
40° from the normal
50° from the surface of the mirror
90° from the normal
if it is a plane mirror, then 40 deg from the surface.
To determine the direction of the reflected ray when a light ray strikes a plane mirror, you need to understand the law of reflection. According to this law, the angle of incidence (i) is equal to the angle of reflection (r). The angle of incidence is the angle between the incident ray and the normal (an imaginary line perpendicular to the surface of the mirror).
In this case, the angle of incidence is given as 50° from the normal. Therefore, the angle of reflection will also be 50° from the normal, but on the opposite side of the mirror. Thus, the correct direction for the reflected ray is 50° from the normal on the opposite side.
Please note that the normal is an imaginary line drawn perpendicular to the surface of the mirror at the point of incidence (the point where the light ray strikes the mirror).