If the ratio of the amplitudes of two interfering sources is $3 : 5$,then the ratio of the intensity of maxima and minima in the interference pattern will be

Two waves of intensity ratio $1:9$ cross each other at a point. The resultant intensities at the point are $I_1$ when the waves are incoherent and $I_2$ when the waves are coherent with a phase difference of $60^{\circ}$. If $\frac{I_1}{I_2} = \frac{10}{x}$,then $x = . . . . . . . . . . .$

The path difference between two interference waves at a point on a screen is $11.5 \lambda$. The point is

To produce the phenomenon of interference,we require two sources that emit radiation of:

If two sources emit light waves of different amplitudes, then:

Among the two interfering monochromatic sources $A$ and $B$; $A$ is ahead of $B$ in phase by $66^\circ$. If the observation is taken from point $P$,such that $PB - PA = \lambda / 4$. Then the phase difference between the waves from $A$ and $B$ reaching $P$ is.....$^\circ$.