Considering interference between two sources of intensities $I$ and $4I$,the intensity at a point where the phase difference is $\pi$ is $(\cos \pi = -1)$.

The two interfering waves have intensities in the ratio $9 : 4$. The ratio of intensities of maxima and minima in the interference pattern will be

Two coherent sources of intensity ratio $9:4$ produce interference. The intensity ratio of maxima and minima of the interference pattern is

Two identical coherent sources are placed on a diameter of a circle of radius $R$ at a separation $x (x << R)$,symmetrically about the center of the circle. The sources emit waves of identical wavelength $\lambda$. Find the number of points on the circle with maximum intensity,given $x = 5 \lambda$.

If the distance between a point source and a screen is doubled,then the intensity of light on the screen will become:

For a distinct interference pattern to be observed,the necessary condition is that the ratio of the intensity of light emission by both sources should be