Question

Determine the slit width that produces a diffraction pattern with the 2nd dark fringe at 6.2mm from the central fringe. The screen distance is 1.25m and the light wavelength is 600nm.

Answer 1

d= 0.242 mm

Step-by-step explanation:

Slit width (d ) = ?

Screen distance ( D ) = 1.25 m

Wave length of light λ = 600 nm

Distance of n the dark fringe from centre

= n λ D / d

Here n = 2

so

`6.2*10^(-3)=(2*600*10^(-9))/(d)`

`d=(1500*10^(-6))/(6.2)`

d= 0.242 mm