Question

In a two-slit interference pattern with λ = 6000 A, the zero order and tenth order

maxima fall at 12.34 mm and 14.73 mm respectively. Find the fringe width.
please answer me fast...​

Answer 1

It is given that in a two - slit interference pattern with λ = 6000 Å the zero order and 10th order Maxima fall at 12.34 mm and 14.73 mm respectively.

we have to find the fringe width.

we know, the interference fringe width for a double slit is given by, γ = Dλ/2d

we also know, nth order Maxima, X_n = 10Dnλ/2d

so, zero order Maxima , X_0 = 0 = 12.34 mm,

10th order Maxima , X_10 = 10Dλ/2d = 14.73 mm,

X_10 - X_0 = 14.73 mm - 12.34 mm = 2.39mm

⇒10Dλ/2d = 2.39 mm

⇒Dλ/2d = 2.39/10 = 0.239 mm

therefore, fringe width of given Young's double slit interference is 0.239 mm