What type of mirror is used by motorists to see road behind them?

Question

What type of mirror is used by motorists to see road behind them?

1. A. Convex (Correct answer)
2. B. Concave
3. C. Plain
4. D. Concavo-Convex

Correct Answer

Option A — Convex

Detailed Solution & Explanation

The correct answer is Convex.

Key Points

• Vehicles use convex mirrors as rear-view mirrors because they always produce an erect, virtual and diminished image.
• Being diminished, the image covers a much wider field of view than a plane mirror of the same size, letting a driver see more of the road behind.

Additional Information

• The trade-off is that objects appear smaller and therefore farther away than they are — the reason for the warning "objects in mirror are closer than they appear".
• Concave mirrors are used where magnification is wanted: shaving and make-up mirrors, dentists' mirrors, torch and headlight reflectors, and solar cookers.
• A convex mirror's focus lies behind the mirror, which is why it can never form a real image.