National League for Nursing (NLN) Science Practice Exam

Light hits a smooth mirror at an angle of 45 degrees. At what angle will the light be reflected?

1. 0 degrees

2. 180 degrees

3. 45 degrees

4. 90 degrees

The correct answer is: 45 degrees

When light encounters a mirror, it follows the law of reflection, which states that the angle of incidence is equal to the angle of reflection. In this case, if the light hits the mirror at an angle of 45 degrees relative to the normal (an imaginary line perpendicular to the surface of the mirror), it will reflect off the mirror at the same angle of 45 degrees in the opposite direction. This means that if the incident angle is 45 degrees, the reflected angle will also be 45 degrees. This principle is fundamental in optics and is commonly applied in various applications, including the functioning of mirrors in everyday life, such as in cars and bathrooms. It's essential to remember that the angles are measured relative to the normal, not the mirror's surface. Thus, the correct response indicating that the light will be reflected at an angle of 45 degrees is accurate based on the law of reflection.