In the interference pattern,energy is

The frequency of a light wave with a wavelength of $500 \, \mathring A$ is $....... \, Hz$.

The total energy carried by a light wave when it travels from a rarer to a non-reflecting and non-absorbing medium:

Two coherent monochromatic light beams of intensities $I$ and $4I$ are superposed. The maximum and minimum possible intensities in the resulting beam are

Two periodic waves of intensities $I_{1}$ and $I_{2}$ pass through a region at the same time in the same direction. The sum of the maximum and minimum intensities is

Write down the principle of superposition and what is interference? Write down its types.