FIZEAU'S principle of determination of the velocity of light can be used for the measurements of lengths. In modern form an arrangement according to this principle is shown in Fig. 1.

There are seven colours of the visible light spectrum. In order of their frequency, from the lowest frequency (fewest waves per second) to the highest frequency (most waves per second), they are ...

You need to know about these quantities used in waves - what they mean, the symbols used for them and the units used to measure them. Don't get confused with this quantity frequency. It is not a ...