Which of the following is NOT the correct use of a concave mirror?
It is used as a rear view mirror in automobiles.
A concave mirror is a converging mirror: it can produce a magnified, erect image of a nearby object and can focus parallel rays (like sunlight) to a point. These properties decide its uses.
A rear view mirror in automobiles is actually a convex mirror, not a concave one. A convex mirror always gives an erect, diminished image and a wider field of view, letting the driver see more of the traffic behind. So using a concave mirror as a rear view mirror is the incorrect statement.
The other options are genuine uses of a concave mirror: as a shaving mirror it gives an enlarged, upright image of the face when held close; in torches and headlights the bulb is placed at the focus so the reflected rays form a strong parallel beam; in a solar furnace it concentrates sunlight to a focal point to produce intense heat.
Hence, the use that is NOT correct is that of a rear view mirror in automobiles.
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