Assertion – There is a definite relationship between focal length and radius of curvature of a spherical mirror.

Reason – Radius of curvature is twice the focal length ( R = 2 f )

Assertion – Mirror's formula cannot be applied to a plane mirror.

Reason – A plane mirror is a spherical mirror of infinite focal length.

Assertion – A convex lens is made of two different materials. An object is placed on the principal axis. The number of images formed by the lens will be two.

Reason – The different materials of the lens will refract the light rays to different extent due to their different optical densities.

Assertion – Light travels faster in glass (refractive index - 1.5) than in water (refractive index - 1.33).

Reason – Glass is more optically denser than water.

Assertion – Virtual images cannot be obtained on a screen.

Reason – virtual images are erect.

Assertion – A ray incident along the normal to the mirror will retraces its path.

Reason – Angle of incidence is always equal to the angle of reflection.

Assertion – It is not possible to see virtual images by our eyes.

Reason – The rays that seems to be coming from the virtual image do not in fact emerges from the image.

Assertion – Concave mirrors are used as make-up mirrors.

Reason – When the face is held between the focus and the mirror, a diminished image of the face can be seen in the mirror.

Assertion – The centre of curvature of a spherical mirror is not a part of the mirror. It lies outside the mirror.

Reason – The reflecting surface of a spherical mirror is a part of an imaginary sphere. The sphere has a centre.

Assertion : Light changes its direction when it travels from one medium to the other having different optical densities.

Reason : The speed of light does not change as it travels from one transparent media to the other.