Quiz on lenses

This is a timed quiz. You will be given 120 seconds to answer all questions. Are you ready?

120

If the focal length of a lens is 20 cm, its optical power is:

+20 diopters

+5 diopters

-5 diopters

-20 diopters

Correct! Wrong!

The focal length of a convex lens is:

Always negative

Always positive

Zero

Dependent on the object distance

Correct! Wrong!

In a concave lens, the image formed is:

Always virtual and upright

Always real and inverted

Real and inverted

Always magnified

Correct! Wrong!

What type of lens is thicker in the middle and thinner at the edges?

Concave lens

Convex lens

Plane mirror

Cylindrical lens

Correct! Wrong!

The optical power of a lens is defined as:

The distance between the object and the lens

The ability to focus light

The inverse of the focal length in meters

The thickness of the lens

Correct! Wrong!

The image formed by a convex lens when the object is placed beyond 2F is:

Virtual and magnified

Virtual and diminished

Real and diminished

Real and magnified

Correct! Wrong!

A concave lens causes light rays to:

Converge

Diverge

Reflect

Absorb

Correct! Wrong!

Which type of lens converges light rays to a single point?

Convex lens

Concave lens

Cylindrical lens

Plano-convex lens

Correct! Wrong!

Quiz on lenses

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