Two beams of light having intensities $I$ and $4I$ interfere to produce a fringe pattern on a screen. The phase difference between the two beams are $\pi/2$ and $\pi/3$ at points $A$ and $B$ respectively. The difference between the resultant intensities at the two points is $xI$. The value of $x$ will be.

The intensities of two coherent sources are $9I$ and $4I$. The intensity at a point where the path difference is $11\lambda$ is:

Two light sources have amplitudes $a$ and $2a$ respectively. If they interfere with a phase difference of $\pi$,what is the resultant minimum intensity?

Consider the following statements about interference of light:
$A$. The interference fringes are equally bright and equally spaced.
$B$. At the centre of a bright fringe,the intensity is four times the intensity of the incident wave.
$C$. For constructive interference of two waves,the crest of one wave coincides with the trough of another wave.
Which of the above statements are correct?

Two waves having intensity $I$ and $9I$ produce interference. If the resultant intensity at a point is $7I$,what is the phase difference between the two waves?........$^o$

Two identical radiators have a separation of $d = \lambda /4$ where $\lambda$ is the wavelength of the waves emitted by either source. The initial phase difference between the sources is $\pi /4$. Then the intensity on the screen at a distant point situated at an angle $\theta = 30^\circ$ from the radiators is (here $I_o$ is the intensity at that point due to one radiator alone):