Question

A He-Ne laser (wavelength λ = 600 nm) shines through a double slit of unknown separation d onto a screen 1.44 m away from the slit. The distance on the screen between the m = 4 maxima and the central maximum of the two-slit diffract

Answer 1

Answer:

1.28 ×10^-4m

Explanation:

Interference is the superimposition of the wavefront. The superimposition causes bright and dark fringes.

The dark fringe is formed when the additional distance traveled is equal to the multiple wavelength integrals.

From the question, the parameters given are; Wavelength of the light,λ= 600nm, Distance of the screen (D) = 1.44m, order of the bright fringe (m) = 4, Distance of the 4 order fringe (y) = 2.7 cm.

Therefore, for the maximum bright fringe;

dy/D=mλ-----------------------------------------------------------------------------------------------------------------------(1)

Therefore, slotting in equation (1);

d×0.027/1.44=4×600×10^-9

d= 1.28×10^-4 m.