Which phenomena can be explained by the wave nature of light?

In the phenomenon of interference,energy.......

The interference pattern is obtained with two coherent light sources of intensity ratio $n$. In the interference pattern,the ratio $\frac{I_{max} - I_{min}}{I_{max} + I_{min}}$ will be

Two light waves of intensities $I$ and $4I$ superpose at a point with a phase difference of $\pi / 2$. Calculate the resultant amplitude at that point.

Two identical light waves having phase difference $\phi$ propagate in the same direction. When they superpose,the intensity of the resultant wave is proportional to:

Two light sources have amplitudes $a$ and $2a$ respectively. If they interfere with a phase difference of $\pi$,what is the resultant minimum intensity?