Which of the following mirrors is commonly used in torches and vehicle headlights?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Concave mirror
The bulb of a torch or headlight is placed at the focus of a concave mirror. Light from the focus is reflected by the mirror as a powerful parallel beam, which lights up the road far ahead.
Why the other options are incorrect
Option (2) Convex mirror — Incorrect. A convex mirror spreads light out; it is used as a rear-view mirror in vehicles because it shows a wide area.
Option (3) Plane mirror — Incorrect. A plane mirror only reflects light without focusing it, so it cannot form a strong parallel beam.
Option (4) All of these — Incorrect. Only the concave mirror gives the parallel beam needed.