What are coherent sources ? Define interfernece of light. Obtain the condition for constructive and destructive interference of light .

State the conditions for constructive and destructive inter-ference of light.

State the condition for constructive interference.

What is the condition of phase difference for destructive interference?

State the importance of coherent sources in the phenomenon of interference. In Young's double slit expet-ment to produce interference pattern obtain the conditions for constructive and destructive interference. Hence deduce the expression for the fringe width. How does the firinge width get affected, if the entire experimental apparatus of Young's is immersed in water ?

Write the relationship between the path difference and the wavelength of light used for constructive and destructive interference of light.

What is the relation between phase difference and path difference ? The path difference at a point on the screen from two coherent sources is 5lambda//2 . Describe the possiblities of constructive and destructive interference at that point if the phase difference between the sources is either (i) pi or (ii) 2 pi .

Define the term coherence for light waves.