However, if
the two needles do not maintain a constant phase difference, then the
interference pattern will also change with time and, if the phase difference
changes very rapidly with time, the positions of maxima and minima will
also vary rapidly with time and we will see a “time-averaged” intensity
distribution When this happens, we will observe an average intensity
that will be given by
I = 2 I0
(10 12)
at all points Ripple Tank experiments on wave interference
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