Lakhmir Singh and Manjit Kaur Solutions for Chapter: Refraction of Light, Exercise 33: Long Answer Type Questions

What do you understand by the power of lens? Name one factor on which the power of a lens depends.

What is the unit of power of lens? Define the unit of power of a lens.

A combination of lenses for a camera contains two converging lenses of focal lengths $20 \mathrm{cm}$ and $40 \mathrm{cm}$ and a diverging lens of focal length $50 \mathrm{cm}$. Find the power and focal length of the combination.

Two lenses $A$ and $B$ have power of (i) $+2 \mathrm{D}$ and (ii) $-4 \mathrm{D}$ respectively. What is the nature and focal length of each lens?

An object is placed at a distance of $100 \mathrm{cm}$ from each of the  lenses $A$ and $B$ having power $+2 \mathrm{D}$ and $-4 \mathrm{D}$ respectively. Calculate (i) image distance and (ii) magnification, in each of the two cases.