Single correct · +4 / −1

The image formed by a plane mirror is:

  1. (a) real, inverted
  2. (b) virtual, erect, same size
  3. (c) real, diminished
  4. (d) virtual, magnified
Answer and solution

Answer (b) virtual, erect, same size

Solution

Physics sir · 4 steps

Reflected rays only seem to come from behind the mirror, and a flat mirror never bends the picture.

  1. Virtual. Rays from the object reflect and spread out. They never actually meet behind the mirror; only their backward extensions do, so the image is virtual and cannot be caught on a screen.
  2. Same size. For a plane mirror the image is as far behind the mirror as the object is in front, so v = -u. The magnification is m = -v/u = +1.
  3. Erect. Since m = +1 is positive, the image is upright, and since its magnitude is 1, the image has the same size as the object.
  4. So. The image formed by a plane mirror is virtual, erect and of the same size, which is option (b).

The idea to keep. A plane mirror always gives m = +1: virtual, erect, same size, as far behind as the object is in front. Only lateral inversion (left and right swap) changes.

Answer from the NTA final answer key. Solution by PrepWiser.

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