Question

Which mirror is used in headlights of cars? At what position is bulb placed in it and why?

Answer 1

Mirror:

The mirror is a reflective surface that reflects back light rays falling on it and produces an image of an object in front of it. The mirror may have a flat surface or a curved surface. A mirror with a flat surface is called a plane mirror whereas spherical mirrors are formed from the surface of a sphere, which has curved surfaces. there are two types of spherical mirrors.

1. Concave mirror: The reflecting surface is curved inwards. This mirror is also known as a converging mirror because if a parallel beam of light falls on this mirror after reflection rays converge to a single point called the focus. Concave mirrors are found in magnifying glass, and telescopes.
2. Convex mirror: The reflecting surface is curved outwards. This mirror is also known as a diverging mirror because if a parallel beam of light falls on this mirror after reflection rays diverge and appear to diverge from a single point called the focus. Convex mirrors can be seen in the side view mirror of vehicles.

Explanation:

1. Concave mirrors are used in the headlights of cars to produce a parallel beam of light covering a longer distance on the road.
2. The bulb is placed at the focus point of the mirror because the light rays that pass through the focus of a concave mirror get reflected as rays parallel to the principal axis of the mirror.
3. This produces a high beam of reflected light and makes the road clearly visible to the driver.