Lenses

If the light ray passes through focus of a lens after refraction it passes

• Parallel to principal axis

• Through optical centre

• Undeviated

Which lens is called converging lens?

• Concave

• Convex

• Plano concave

If an object is placed between F and 2F of a Concave lens, What will be the nature of the image?

• Real and magnified

• Virtual and magnified

• Virtual and diminished

If an object is placed between F and 2F of a Concave lens, What will be the nature of the image?

• Real and magnified

• Virtual and magnified

• Virtual and diminished

In order to get the image size as same as size of the object, where should an object placed in front of convex lens?

• At infinity

• At focus

• At centre of curvature

Which lens is used to treat hyper metropia?

• Convex

• Concave

What is the sign convention for the distances measured along the direction of incident light?

• Positive

• Negative

Which lens is used as spy lens in door?

The unit of power of lens is

If magnification is less than one (m<1) then the size of the image is

• Enlarged

• Diminished

• Same size as object