Assertion – A ray of light travelling from a denser medium to a rarer medium bends towards the normal.

Reason – The speed of light is higher in a rarer medium than a denser medium.

Assertion – A convex mirror is a diverging mirror.

Reason –Incident rays parallel to the principal axis meet at a point on the principal axis  after reflection from the convex mirror. 

Assertion – The height of an object is always considered positive.

Reason – An object is always placed above the principal axis in the upward direction.

Assertion –Incident ray is directed towards the centre of curvature of a spherical mirror. After reflection it retraces its path.

Reason –Angle of incidence (i) + angle of reflection (r) = 180°

Assertion – Large concave  mirror are used to concentrate sunlight to produce heat in solar cookers.

Reason – Concave mirror converges parallel beam of light falling on it to a point

Assertion – SI unit of refractive index is \( ms^{-1}\).

Reason – The speed of light in vacuum is \( 3\times 10^{8}\;ms^{-1}\) and it becomes less than \( 3\times 10^{8}\;ms^{-1}\) in any other medium.

Assertion – Magnification of a real image is negative but magnification of virtual image is positive.

Reason – Real image is an inverted image but virtual image is erect image.

Assertion – A convex lens is called a convergent lens and a concave lens is called a divergent lens.

Reason – A convergent lens always forms a real image and divergent lens always forms a virtual image.

Assertion – Concave mirror has a real focus.

Reason – Focus is a mid-point of pole and centre of curvature.

Assertion – In concave mirror, the minimum distance between the object and its real image is zero.

Reason – Image is obtained at the centre of curvature when object is placed at the centre of curvature of the concave mirror.