1Compare the speed of light in water and kerosene oil. Which of the two is the optically denser medium?
2Does an optically denser medium mean a medium with a higher physical density?
3Why does a pencil partly dipped in water look bent at the water surface?
4Why do air bubbles inside water shine like a mirror?
5On what principle is optical fibre constructed?
6Why do letters look larger when viewed through a hand lens?
7What happens to sunlight when a rainbow forms, and which part of the eye helps us see its seven colours?
8Give two reasons why vision becomes blurred. How is the problem of not seeing distant or nearby objects solved?
9What is a transparent medium? Give three examples.
10Define denser medium and rarer medium. In the pair air and glass, which is denser and which is rarer?
11"Water is a denser medium." Is this statement complete? Give a reason.
12In the pair diamond and glass, which is the denser medium? Show by comparing speeds.