Physics 2004 JAMB Past Questions - Question 2: What types of mirrors are capable of producing parallel beams of light such as those arising from the headlamps of a car?

Correct Answer

A

Explanation

To produce parallel beams of light, you would typically use mirrors with a specific shape or curvature. The type of mirrors that can produce parallel beams of light from a point source (such as a car's headlamp) are:

1. **Concave Mirrors**: Concave mirrors are curved inward and can focus light to a point. When the source of light (like a car headlamp) is placed at the focal point of a concave mirror, the mirror will reflect the light into a parallel beam. Concave mirrors are commonly used in car headlights to produce a parallel beam of light.

2. **Parabolic Mirrors**: A parabolic mirror is a specific type of concave mirror with a parabolic shape. Parabolic mirrors are often used in applications like satellite dishes and telescopes to collect and focus incoming parallel beams of light at a single point. This property can be reversed to create parallel beams from a point source at the focus.

3. **Plane Mirrors**: While plane mirrors don't inherently produce parallel beams of light, they can be used to redirect light from a source in such a way that it forms parallel rays. This involves positioning the plane mirror at a certain angle relative to the light source to reflect the light in a desired direction. Plane mirrors are often used in car headlights to adjust the direction of the light beams.

4. **Front Surface Mirrors**: Front surface mirrors are designed to minimize double reflection (caused by the reflection of light from both the front surface and the underlying glass) and are used in precision optics. They can be used to produce parallel beams of light by proper alignment and placement.

The choice of mirror will depend on the specific application and the desired characteristics of the parallel light beams, such as the size and distance of the source and the intended focal point or direction of the beams. In the case of car headlights, concave mirrors and sometimes plane mirrors are commonly used to achieve parallel beams.