Question

Why a convex lens has positive focus?
Class 10th

Answer 1

Ans ➡️ Convex lenses have positive optical power because while diverging lenses have negative power. When a lens is immersed in a refractive medium, its optical power and focal length change.

Hope this helps you mate ☺️☺️✌️✌️✅✅

Answer 2

Why a convex lens has positive focus?

Good question,

Here is your perfect answer!

According to sign convention rule,

The distance is measured from origin as pole.

The direction of an incident ray is taken as positive and opposite as negative.

Since convex lens is converging, it has focus behind it (right, if light comes from left to right).

So it has positive focus.