What is the difference between focus and principal focus of concave and convex lenses
What is the difference between focus and principal focus.
How is the main focus of BPO services different from the focus of KPO services ?
Draw ray diagrams showing the image formation by a convex lens when an object is placed (a) between optical centre and focus of the lens (b) between focus and twice the focal length of the lens (c) at twice the focal length of the lens (d) at infinity (e) at the focus of the lens