Identify the mirrors on the basis of information given in the following table…
2024
Identify the mirrors on the basis of information given in the following table :
Mirror | Nature of image | Size of image |
|---|---|---|
A | virtual and erect | same as object |
B | real and inverted | same as object |
C | real and inverted | enlarged |
D | virtual and erect | diminished |
- A.
A - Plane, B - Convex, C - Concave, D - Convex
- B.
A - Convex, B - Concave, C - Convex, D - Concave
- C.
A - Plane mirror, B - Concave, C - Concave, D - Convex
- D.
A - Concave, B - Plane, C - Convex, D - Concave
Show answer & explanation
Correct answer: C
Concept
The nature (real/virtual, erect/inverted) and size (same/enlarged/diminished) of the image formed by a mirror depend on its type. A plane mirror always forms a virtual, erect image equal in size to the object. A convex mirror always forms a virtual, erect, diminished image. A concave mirror can form several different images depending on the object's distance: a virtual, erect, enlarged image when the object is within the focus; a real, inverted, enlarged image when the object is between the focus and the centre of curvature; a real, inverted, same-size image when the object is at the centre of curvature; and a real, inverted, diminished image when the object is beyond the centre of curvature.
Application
Mirror A gives a virtual, erect image the same size as the object. Only a plane mirror always produces this exact combination for every object position, so A is a plane mirror.
Mirror B gives a real, inverted image the same size as the object. A real image rules out both plane and convex mirrors (neither ever forms one), so B must be concave; a concave mirror gives a same-size real image specifically when the object sits at the centre of curvature.
Mirror C gives a real, inverted, enlarged image. This particular combination occurs for a concave mirror when the object lies between the focus and the centre of curvature, so C is also concave.
Mirror D gives a virtual, erect, diminished image. Diminishing a virtual, erect image is the one behaviour unique to a convex mirror, so D is a convex mirror.
Cross-check
A convex mirror never forms a real image and never enlarges or keeps an image the same size — this rules out convex for A, B, and C, consistent with the assignment above.
A plane mirror never forms a real image and never changes the image size — this rules out plane for B, C, and D, again consistent with the assignment above.
Every mirror in the table is therefore accounted for by exactly one type, with no contradictions: A - Plane, B - Concave, C - Concave, D - Convex.