A spherical mirror forms an image of magnification 3. The object distance, if focal length of mirror is `24cm,` may be

Options

A. `32cm, 24 cm`
B. `32cm, 16 cm`
C. `32 cm ` only
D. `16 cm` only

Answer

B

Explanation

`m=(f)/(f-u)`
`3=(-24)/(-24-u)` or `-24-u=-8` or `u+24=8`
or `u=(8-24)cm=-16cm`
If `m=-3`, then, `-3=(-24)/(-24-u) u+24=-8`
or `u=-32 cm`.
Note that the magnification is greater than one `S_(0)`, mirrorr cannot be convex.