Question

You are given kerosene, turpentine and water. In which of these does the light travel fastest? Use the information given in Table.

Material medium	Refractive index	Material medium	Refractive   index
Air	1.0003	Canada Balsam	1.53
Ice	1.31	–	–
Water	1.33	Rock salt	1.54
Alcohol	1.36	–	–
Kerosene	1.44	Carbon disulphide	1.63
Fused quartz	1.46	Dense flint glass	1.65
Turpentine oil	1.47	Ruby	1.71
Benzene	1.50	Sapphire	1.77
Crown glass	1.52	Diamond	2.42

Answer 1

In water light travel faster as compare to kerosene and turpentine because the refractive index of water is lower than that of kerosene and turpentine. The speed of light is inversely proportional to the refractive index.