1000+ General Knowledge Questions and Answers in English - 2

Question: 6

What are the uses of periscope?

The periscope is used in submarines to see objects above the surface of water.

Question: 7

Give the uses of a simple microscope?

They are used by

(1) watch repairers and

(2) palmists.

They use the convex lens as a simple microscope.

Question: 8

What are optical instruments?

Any arrangement which makes use of a combination of lenses, mirrors or prisms is called an optical instrument. All the optical instruments are based on the laws of reflection and refraction.

Question: 9

What is dispersion of light?

When a beam of white light passes through a prism, it is split up into its constituent colours. This is called dispersion of light.

Question: 10

Define centre of curvature of a lens?

The centre of the sphere of which its surface forms a part is called centre of curvature.