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

If two light waves having the same frequency have an intensity ratio of $4:1$ and they interfere,the ratio of maximum to minimum intensity in the pattern will be:

When two light waves of equal intensity superimpose, the maximum intensity obtained is $I$. If the intensity of one of the waves is quadrupled, then the maximum intensity obtained is

Intensities of the two waves of light are $I$ and $4I$. The maximum intensity of the resultant wave after superposition is (in $I$)

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.

Resultant intensity at the centre of the screen due to two coherent sources is $I_0$. If the sources are incoherent,then the intensity at the same point will be