If $L$ is the coherence length and $c$ is the velocity of light,the coherence time is

Two light rays having the same wavelength $\lambda$ in vacuum are in phase initially. Then the first ray travels a path $L_1$ through a medium of refractive index $\mu_1$,while the second ray travels a path of length $L_2$ through a medium of refractive index $\mu_2$. The two waves are then combined to observe interference. The phase difference between the two waves is

Two coherent sources of different intensities send waves which interfere. The ratio of maximum intensity to the minimum intensity is $25$. The intensities of the sources are in the ratio:

Consider the interference of two sources with intensities $I$ and $4I$. Find the intensity at a point where the phase difference is $\pi/2$. (in $I$)

Two coherent sources of light can be obtained by

Two light waves of intensities $I_1$ and $I_2$ having the same frequency pass through the same medium at a time in the same direction and interfere. The sum of the minimum and maximum intensities is