The direction of a ray of light incident on a concave mirror is shown by $PQ$,while the directions in which the ray would travel after reflection are shown by four rays marked $1, 2, 3,$ and $4$. Which of the four rays correctly shows the direction of the reflected ray?

The focal length of a concave mirror is $50 \, cm$. Where should an object be placed so that its image is two times magnified and inverted?

What can be the largest distance of an image of a real object from a convex mirror of radius of curvature $10\,cm$?

Define the following for curved mirrors: $(1)$ Radius of curvature,$(2)$ Centre of curvature,$(3)$ Pole,$(4)$ Principal axis,$(5)$ Aperture,$(6)$ Principal focus,$(7)$ Focal plane,$(8)$ Focal length,$(9)$ Paraxial rays.

An object is placed at a distance of $f$ from the pole of a convex mirror of focal length $f$. Where will the image be formed?

The separation between the screen and a concave mirror is $2r$. An isotropic point source of light is placed exactly midway between the mirror and the screen. The mirror has a radius of curvature $r$ and reflects $100\%$ of the incident light. Find the ratio of illuminances on the screen with and without the mirror.