1. | Twinkling of stars is due to atmospheric ? | |
2. | The bluish colour of water in deep sea is due to ? | |
3. | The focal length of the eye lens increases when eye muscles ? | |
4. | The clear sky appears blue because ? | |
5. | A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power ? | |
6. | At noon the sun appears white as ? | |
7. | The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light ? | |
8. | When light rays enter the eye, most of the refraction occurs at the ? | |
9. | At noon, the Sun appears white as ? | |
10. | Cornea is a transparent spherical structure which ____ ? | |