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Question

Monochromatic light with a wavelength of 6.4 E -7 meter passes through two narrow slits, producing an interference pattern on a screen 4.0 meters away. The first order bright band lines are 2.0 E -2 meters away from the central bright maxima.

What is the distance between the slits?

Answer 1

lambda = XS/D

where: lambda=wavelength, X=distance between band lines, S=slit separation, D=distance between pattern and screen.

substitute:

6.4 E -7 = (2.0 E -2)S / 4

S = 1.28 E -4