If two waves are superposed at `180^@` phase difference then what will be the nature of interference?

If the path difference is lambda , what will be the phase difference?

What is the path difference between two waves for destructive interference?

What is the path difference between two waves for constructive interfernce?

What is the phase difference between any two points on the same wavefront?

What is the phase difference between two points situated on a wavefront ?

Two sound waves having phase difference of 60^@ have path difference of

The ratio of amplitude of two waves having the same frequency is 1:3. These two waves are superposed. Determine the ratio of the maximum and minimum intensities.

what idea does diffraction of light give about the nature of light waves?