IN DIFFRACTION THERE IS ONE SLIT WHICH ACCOUNTS FOR INFINITE NUMBER OF SOURCES

BUT IN INTERFERENCE THERE ARE TWO SLITS SO WHY SHOULD IT NOT ACCOUNT FOR TWO INFINTE NUMBER OF SOURCES AND ONLY TWO SOURCE? PLS EXPLAIN WITH DIAGRAMS.

In diffraction, there is one slit whose width is comparable to the wavelength of the light used. The source of light emerges from the slit with infinite wavefronts. Hence, we say that the slit acts as infinite sources.

 

In interference there are two slits, whose wavefronts are similar to that in diffraction. So, ideally we have two infinite sources only. But, interference is only considered when there is superposition between the wavefronts of these sources. Hence, technically we say that there are two sources in interference.