Question

State the differences between a convex and a concave lens.

Answer 1

Differences between a concave and a convex lens are

Concave lens	Convex lens
1. It diverges the incident rays away from the principal axis.	1. It converges the incident rays towards the principal axis.
2. A concave lens is thinner in the middle and thicker at the edges.	2.A convex lens is thicker in the middle and thinner at the edges.
3. It has negative focal length	3. It has positive focal length
4. It can produce real as well as virtual images.	4. It always produce a virtual image
5. The image formed is an upright, virtual, and smaller size than the object.	5. The image formed is inverted, real and larger than the object when the object is placed between optical center and focus. The image formed is virtual, erect and smaller size when the object is placed beyond focal length.
6. Used in correction of myopia or short sight	6. Used in correction of hypermetropia or long sight
7. Used in glasses, some telescopes, spy holes in the doors, etc.	7. Used in the camera, focus sunlight, overhead projector, projector microscope, simple telescope, magnifying glasses, etc.