An object $\mathrm{PQ}$ stands on the principal axis of a convex mirror as shown in figure copy the diagram and complete it to show the formation of the image. Is the image virtual? 

                                                                                            

 

An image of the sun is cast on a white screen by a concave mirror. What change will be observed in the image if the aperture of the mirror is gradually reduced?

Two rays $a$ and $b$ reflected by a mirror go along $a\text{'}$ and $b\text{'}$. What is the nature of the mirror? What is its position?

Define the focus in connection with a concave mirror.

Define the focal length in connection with a concave mirror.

Define the radius of curvature in connection with a concave mirror. 

Define the centre of curvature in connection with a concave mirror.

Define the pole in connection with a concave mirror.

Define the conjugate pair of foci in connection with a concave mirror.