Which characteristic of light determines its color?

Two monochromatic light waves of amplitudes $3A$ and $2A$ interfering at a point have a phase difference of $60^{\circ}$. The intensity at that point will be proportional to.......$A^2$

The ratio of maximum and minimum intensities in an interference pattern is $36: 1$. The ratio of the amplitude of the two interfering waves will be

Two coherent sources of intensity ratio $1 : 4$ produce an interference pattern. The fringe visibility will be

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.

Which of the following is the path difference for destructive interference?