Concave mirror is used in headlights of vehicles, because it

Concave mirrors are used in vehicle headlights because of their unique reflective properties. When a light source, such as a bulb, is placed at the focal point of a concave mirror, the reflected rays emerge as a powerful parallel beam [1]. This occurs because the concave mirror is a converging mirror; it redirects light from the focus into a specific, directed path rather than allowing it to scatter. This parallel beam ensures high-intensity illumination over long distances, which is essential for driver safety and visibility at night. While these mirrors are also used in torches and searchlights for the same reason, their primary function in automotive headlights is to project light far ahead on the road by sending parallel rays [1].

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 9: Light – Reflection and Refraction > Uses of concave mirrors > p. 140