If the ratio of maximum and minimum intensities is $36 : 1$ in an interference pattern,then the ratio of amplitudes of the interfering waves is

Light waves producing interference have their amplitudes in the ratio $3: 2$. The intensity ratio of maximum and minimum of interference fringes is

Four monochromatic and coherent sources of light,emitting waves in phase of wavelength $\lambda$,are placed at the points $x = 0, d, 2d$,and $3d$ on the $x$-axis. The intensity of the waves reaching a point $P$ far away on the $+x$ axis from each of the four sources is almost the same,and equal to $I_0$. Then,

Consider the following statements about interference of light.
$A$-When crest of one wave coincides with crest of another wave at a point,this point is a point of destructive interference.
$B$-Two coherent sources emit waves of the same frequency with a constant phase difference.
Choose the correct option from the following.

The contrast in the fringes in an interference pattern depends on

Two coherent sources of intensities $I$ and $4I$ interfere. The maximum and minimum intensities of the resultant wave are: