Question

how can you differentiate between convex and concave lens when they are on table and without touching them(any three points)​

Answer 1

Answer:

A concave lens is thinner in the middle and thicker at the edges. A convex lens is thicker in the middle and thinner at the edges. Used in the camera, focus sunlight, overhead projector, projector microscope, simple telescope, magnifying glasses, etc.

Answer 2

We can differentiate between a convex and concave lens by seeing the image.

• On keeping the lens near a printed page, if letters appear magnified, the lens is convex and if the letters appear diminished, the lens is concave.
• On seeing a distant object through the lens, if its inverted image is seen, the lens is convex and if an upright image is seen, the lens is concave.