In the phenomenon of interference:

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

Two coherent sources separated by a distance $d$ are radiating in phase with a wavelength $\lambda$. $A$ detector moves in a large circle around the two sources in the plane of the two sources. The angular position of the $n = 4$ interference maxima is given as

Two light waves of intensities $I$ and $2I$ superimpose on each other. If the path difference between the light waves reaching a point is $12.5 \%$ of the wavelength of the light,then the resultant intensity at the point is (Both the light waves have same wavelength).

Two coherent sources of intensities,$I_1$ and $I_2$ produce an interference pattern. The maximum intensity in the interference pattern will be

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 $x = 5 \lambda$.