Two waves coming from two coherent sources,having different intensities,interfere. The ratio of their maximum intensity to the minimum intensity is $25$. What is the ratio of the intensities of the sources?

$A$ 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 $n = 1, 2, \dots$)

For constructive interference to take place between two monochromatic light waves of wavelength $\lambda$, the path difference should be

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 $I$)

$A$ laser is a coherent source because it contains

The resultant amplitude of coherent sources depends on ......