In the double-slit experiment of figure a below, monochromatic orange light of w
ID: 1613698 • Letter: I
Question
In the double-slit experiment of figure a below, monochromatic orange light of wavelength 600 nm illuminates the two parallel narrow slits S1 and S2. The slits are d = 7.40 m apart. Waves from the slits (which extend into and out of the page) combine at P, an arbitrary point on screen C at distance y from the central axis. The angle serves as a convenient locator for P. For D d, we can approximate rays r1 and r2 as being parallel, at angle to the central axis (figure (b)).
(a) Calculate the angular deviation of the third-order (for m = 3) bright fringe in radians.
rad
(b) What is this value in degrees?
°
Explanation / Answer
a) The given wave length = 600nm
the seperation between the slits d = 7.40m
Using condition for bright fringes
dsin = m
hence
sin = m/d = (3)(600*10^-9)/(7.40*10^-6)
= 0.2432 rad
b) = 13.94o