Question

The power of a lens used in a reading glass of a person is $+1D$. What is the nature of the lens?

Answer 1

1. The power of the lens$\left(P\right)$ shows the converging or diverging properties of a lens and it is the reciprocal of the focal length$\left(f\right)$ of the lens. Mathematically, $P=\frac{1}{f}$.
2. As the power of the lens is positive, the focal length of the lens will be positive too.
3. Thus, the nature of the lens is convex as the convex lens has a positive focal length.