Question
Sat May 07, 2011

# What are coherent light sources ?

Sat May 07, 2011
Two sources of light are said to be coherent if the waves emitted from them have the same frequency and are 'phase-linked'; that is, they have a zero or constant phase difference.

When interfering, two waves can add together to create a larger wave (constructive interference) or subtract from each other to create a smaller wave (destructive interference), depending on their relative phase. Two waves are said to be coherent if they have a constant relative phase. The degree of coherence is measured by the interference visibility a measure of how perfectly the waves can cancel due to destructive interference.
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# Expert, I am a CBSE class 12 student. My query is regarding which book I should follow. My teachers are following different guides and the derivations they teach are different from those of the text books. Moreover textbook derivations are short and complicated.Which one should I follow? My doubt is with respect to CBSE class 12 examination.

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