Interference fringes are produced on a screen by using two light sources of intensities $I$ and $9I$. The phase difference between the beams is $\frac{\pi}{2}$ at the point $P$ and $\pi$ at the point $Q$ on the screen. The difference between the resultant intensities at point $P$ and $Q$ is (in $I$)

Two light rays having the same wavelength $\lambda$ in vacuum are in phase initially. Then the first ray travels a path $L_1$ through a medium of refractive index $\mu_1$,while the second ray travels a path of length $L_2$ through a medium of refractive index $\mu_2$. The two waves are then combined to observe interference. The phase difference between the two waves is

Which characteristic of light determines its color?

The displacements of two interfering light waves are given by $y_1 = 4 \sin \omega t$ and $y_2 = 3 \sin (\omega t + \frac{\pi}{2})$. What is the amplitude of the resultant wave?

Two beams of light having intensities $I$ and $4I$ interfere to produce fringes on a screen. The phase difference between the beams at point $A$ is $\pi/2$ and at point $B$ is $2\pi$. Find the resultant intensities at points $A$ and $B$.

The path difference between two interfering waves at a point on the screen is $171.5$ times the wavelength. If the path difference is $0.01029 \, cm$,find the wavelength in $\mathring{A}$.