________________
46
Jainism: Through Science as shown in fig, No, 3 which emits spherical waves. In the second screen there are two slits having equal distance from the slit of first screen A. They act as the coherent sources. The waves, having the same frequency, the same amplitude and the same wavelength, passing through both slits S, and S, superpose each other and produce interference. In fig, No. 3, dark lines show the crests of both waves coming from slit No. 1 and Slit No. 2. While dotted lines show the troughs of both waves, coming from both slits. We can see from the figure that when a crest of one wave falls on the crest of the other wave or a trough of one wave falls on the trough of the other wave, a constructive interference takes place and both are denoted by dark points. In the same way when the crest of one wave falls on the trough of another wave or a trough of one wave falls on the crest of the other wave, destructive interference takes place and both are denoted by small circles. By putting a screen in the path of these superposed waves, we get bright fringes on the screen in the straight lines of dark points showing constructive interference of light and dark fringes on the screen, in the straight lines of small circles showing destructive interference.
Fig. No. 3
BRIGHT
DARK
BRIGHT
DARK
BRIGHT