Which of the following statements about light waves is $NOT$ correct?

For driving a car,what type of mirror would you prefer to see the traffic at your back?

$A$ $2.0 \text{ cm}$ tall object is placed perpendicular to the principal axis of a convex lens of focal length $10 \text{ cm}$. The distance of the object from the lens is $15 \text{ cm}$. Find the position,nature,and size of the image formed.

What is the angle of incidence for a light ray incident on a glass slab such that it does not undergo refraction (in $^{\circ}$)?

Refractive index of diamond with respect to glass is $1.6$ and absolute refractive index of glass is $1.5$. Find out the absolute refractive index of diamond.

How are power and focal length of a lens related? You are provided with two lenses of focal length $20\, cm$ and $40\, cm$ respectively. Which lens will you use to obtain more convergent light?