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

The intensity of light depends upon:

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 waves having amplitudes in the ratio $5:1$ produce interference. The ratio of the maximum to minimum intensity is

Interference fringes are produced on the screen by using two light sources of intensities $I$ and $9I$. The phase difference between the beams is $\pi / 2$ at point $P$ and $\pi$ at point $Q$ on the screen. The difference between the resultant intensities at points $P$ and $Q$ is $(\cos 90^{\circ}=0, \cos 180^{\circ}=-1)$. (in $I$)

Two waves of same intensity $I_0$ emitted from two sources having same phase difference $(\phi)$. Due to superposition of two waves, the intensity of resultant wave is directly proportional to . . . . . . .