What is interference of light? Name the interference happen at a place where intensity of light is maximum and minimum. Write four conditions to sustain interference.

Write the relation between phase difference and path difference for two interfering light rays. If path difference between two waves is whole multiple of wavelength, find the corresponding path difference. Define visible/contrast interference.

Describe Young’s double-slit experiment and show that width of bright fringe is equal to width of dark fringe.

Obtain an expression for path difference i.e., $\text{P.D.}=\frac{\mathrm{xd}}{\mathrm{D}}$ where $\mathrm{d}$ is the distance between two sources, $\mathrm{D}$ is the distance of the screen from the slit and $x$ is the distance of the interfering point from the centre of the screen.

If Young’s double-slit experiment set up is immersed in water, what would happen to the width of the fringe?

Define coherent sources and monochromatic light. Name a light which can be considered as monochromatic. Write three values of path difference and corresponding values of phase difference for destructive interference.

Two waves of equal frequencies have their amplitudes in the ratio of $3:5$. They are superimposed on each other. Calculate the ratio of maximum and minimum intensities of the resultant wave.

The two slits in Young’s double-slit experiment have widths in the ratio $9:4$. Find the ratio of light intensities at maxima and minima in the interference pattern.

The intensity ratio of maxima and minima in an interference pattern is $4:1$. Find the ratio of slit widths.