A convex lens of short focal length is often used as a reading glass.
a. (i) Define least distance of distinct vision for a normal human eye.
b. (ii) Explain, with the help of the idea of angular size, how placing an object within the focal length of such a lens allows the eye to see a magnified, virtual image at infinity while the eye remains relaxed.
c. (iii) Giving suitable reasoning (without using a mathematical derivation), state why lenses of smaller focal length provide larger magnifying power under this viewing condition.