(i) (a) 'Two independent monochromatic sources of light cannot produce `a` sustained interference pattern'. Give reason.(b) Light waves each of amplitude a and frequency `omega` emanating from two coherent light sources superpose at a point. If the displacements due to these waves is given by `Y_1 = acosomegat and Y_2 = acos(omegat+phi)` where `(phi)` is the phase difference between the two, obtain the expression for the resultant intensity at the point. (ii) In Young's double slit experiment using monochromatic light of wavelength `lambda`, the intensity of light at a point on the screen where path difference is `lambda`, is K

Question

(i) (a) 'Two independent monochromatic sources of light cannot produce `a` sustained interference pattern'. Give reason.
(b) Light waves each of amplitude a and frequency `omega` emanating from two coherent light sources superpose at a point. If the displacements due to these waves is given by `Y_1 = acosomegat and Y_2 = acos(omegat+phi)` where `(phi)` is the phase difference between the two, obtain the expression for the resultant intensity at the point.
(ii) In Young's double slit experiment using monochromatic light of wavelength `lambda`, the intensity of light at a point on the screen where path difference is `lambda`, is K units. Find out the intensity of light at a point where path difference is `lambda//3`.