Two slits in YDSE are illuminated by two different sodium lamps emitting light of same wavelength. Why do/don't you observe interference pattern ?
Answer & explanation
Correct answer: option 3
When the two slits of Young's double slit experiment are illuminated by two different sodium lamps, then the sources are not coherent and hence sustained interference pattern will not achieved. It will change so quickly that there will be general illuminated and hence interference pattern will no t be observed.