100+ GK Current Affairs Questions and Answers Pdf - 3

Question: 11

What are secondary colours?

The colours obtained by mixing any two primary colours are called secondary colours.

Question: 12

What are primary colours?

The primary colours are red, blue and green because it is not possible to produce these colours by mixing other colours.

Question: 13

What are complimentary colours?

Two colours which mixed in correct proportion give white light are known as complimentary colours.

Question: 14

What is the least distance of distinct vision?

For a normal person the least distance of distinct vision at which the objects are seen clearly is 25 cm (0.25 m). The above distance is called the least distance of distinct vision. Within this range objects cannot be seen clearly.

Question: 15

What is total internal reflection?

When a ray of light travelling from a denser medium into a rarer medium, incident at an angle greater than the critical angle, the ray is totally reflected back in the same medium. This is called total internal reflection.