Which type of lens is thicker at the center than at the edges?

The unit of focal length is:

Which lens is used to correct myopia (short-sightedness)?

The point where parallel rays of light meet after refraction through a convex lens is called:

Which mirror is used in a car’s rear-view mirror?

The power of a lens is measured in:

A concave lens always produces:

The speed of light is maximum in:

Which type of image can a plane mirror form?

A magnifying glass works on the principle of which lens?