An object is placed at a distance 2 f from the pole of a curved mirror (concave or convex) of focal length f . Then :

Question

An object is placed at a distance 2 f from the pole of a curved mirror (concave or convex) of focal length f . Then : (A) the linear magnification is 1, for both types of curved mirrors (B) the linear magnification is 1 for a convex mirror (C) the linear magnification is 1/3 for a convex mirror (D) none of these

Tardigrade Admin · Accepted Answer

For a curved mirror, when object is placed at

2 F

,
the real image of the same size as , that of object is formed at

2 C

.
So, for a concave mirror

m = \frac{- f}{- f - ( - 2 f )} = - 1

For convex mirror,

m = \frac{f}{f - ( - 2 f )} = \frac{1}{3}

Q. An object is placed at a distance 2f from the pole of a curved mirror (concave or convex) of focal length f . Then :

the linear magnification is 1, for both types of curved mirrors

the linear magnification is 1 for a convex mirror

the linear magnification is 1/3 for a convex mirror

none of these

For a curved mirror, when object is placed at 2F, the real image of the same size as , that of object is formed at 2C. So, for a concave mirror m=−f−(−2f)−f​=−1 For convex mirror, m=f−(−2f)f​=31​

Q. An object is placed at a distance $2 f$ from the pole of a curved mirror (concave or convex) of focal length $f$ . Then :

For a curved mirror, when object is placed at $2 F$ ,
the real image of the same size as , that of object is formed at $2 C$ .
So, for a concave mirror $m = \frac{- f}{- f - ( - 2 f )} = - 1$
For convex mirror, $m = \frac{f}{f - ( - 2 f )} = \frac{1}{3}$