In a Young\'s double-slit experiment, a set of parallel slits with a separation
ID: 2034377 • Letter: I
Question
In a Young's double-slit experiment, a set of parallel slits with a separation of 0.102 mm is illuminated by light having a wavelength of 553 nm and the interference pattern observed on a screen 3.50 m from the slits.
(a) What is the difference in path lengths from the two slits to the location of a fourth order bright fringe on the screen?
µm
(b) What is the difference in path lengths from the two slits to the location of the fourth dark fringe on the screen, away from the center of the pattern?
µm
Explanation / Answer
a) for mth bright fringe the distance will be x(bright) = m (lambda) L / d
and since m = 2 , x2 = 2 x 553 x10^-9 x 3.5 / 10^-4 = 40.04 mm
b) for dark fringe x(dark) = ( m+1/2) (lambda) L / d = (2+1/2) x 553 x10^-9 x 3.5 / 10^-4 = 50.05 mm