Question

An object $AB$ is placed parallel and close to the optical axis between focus $F$ and centre of curvature $C$ of a converging mirror of focal length $f$ as shown in figure. Choose the correct statements.

• A. Image of $A$ will be closer than that of $B$ from the mirror.
• B. Image of $AB$ will be parallel to the optical axis.
• C. Image of $AB$ will be straight line inclined to the optical axis.
• D. Image of $AB$ will not be straight line.

Answer 1

Answer: (A), (C)

The correct options are
A Image of $A$ will be closer than that of $B$ from the mirror.
C Image of $AB$ will be straight line inclined to the optical axis.

When a object moves from $C$ to $F$ the image moves from $C$ to $\infty$ and the magnification also goes on increasing.

i.e. The image of a point closer to the focus will be farther. So, the image of $B$ will be farther than image of $A$ from pole of the mirror.

We can consider rod $AB$ as combination of point objects positioned between $A$ and $B$,
Though all object heights from $A$ to $B$ are same, their image heights are all different, as the transverse magnification of object at $B$ will be more than object at $A$.
Thus the image of $AB$ will be inclined to the optical axis.