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

Light waves producing interference have their amplitudes in the ratio $3: 2$. The intensity ratio of maximum and minimum of interference fringes is

Two coherent sources have different intensities. They produce an interference pattern. If the ratio of maximum to minimum intensities is $25:1$,find the ratio of the intensities of the sources.

The ratio of the intensities of two waves is $25 : 1$. If interference occurs,then the ratio of the maximum and minimum intensity should be:

$A$ beam with wavelength $\lambda$ falls on a stack of partially reflecting planes with separation $d$. The angle $\theta$ that the beam should make with the planes so that the beams reflected from successive planes may interfere constructively is (where $n = 1, 2, \dots$)

Interference fringes are produced on a screen by using two light sources of intensities $I$ and $9I$. The phase difference between the beams is $\frac{\pi}{2}$ at the point $P$ and $\pi$ at the point $Q$ on the screen. The difference between the resultant intensities at point $P$ and $Q$ is (in $I$)