This video lecture from Physical Optics (F.Sc. first year physics) covers the concept of monochromatic light, coherent sources and explanation of Interference of light and its types. Also you will know about constructive and destructive interference and formulas of their path difference. Find more e-learning material and educational video lectures in Urdu at maktab.pk. These videos are free to use for promotional and commercial purpose by keeping the credits to Maktab.