A light beam is directed parallel to the axis of a hollow cylindrical tube. When the tube contains only air, the light takes 8.72 ns to travel the length of the tube, but when the tube is filled with a transparent jelly, the light takes 1.82 ns longer to travel its length. What is the refractive index of this jelly?

1.208

Explanation:

L = Length of tube

c = Speed of light in air

v = Speed of light in jelly

Time taken by light in tube

Time taken when jelly is present

Dividing the above equations we get

The refractive index of the jelly is 1.208

igneous rocks also form where plates converge. the subducting plate melts as it sinks into the crust of the earth, and the melt rises into the overriding plate forming volcanoes. metamorphic rocks are formed mainly in the lithosphere, wherever there is high pressure and high temperature. -woods