The image formed by a convex spherical mirror is always:

Through which point of a convex lens does a ray of light pass without undergoing refraction?

The diagram given below shows an object $O$ and its image $I.$ Copy the diagram and draw suitable rays to locate the lens and its focus. Name the type of lens in this case.

When a concave mirror produces a virtual and magnified image of an object,what is the object distance?

You have a spherical mirror. The image of an object placed in front of the mirror is virtual. If the position of the object is changed,the image remains virtual and erect. Is the spherical mirror concave or convex?

What is the centre of a curved mirror called?