Two thin slits are 6.00 μm apart.Monochromatic coherent light falls on these slits,and produces a fifth-order bright interference fringe at an angle of 32.3° away from the centerline.What is the wavelength of the light?
A)164 nm
B)416 nm
C)614 nm
D)641 nm

Question

Quizplus · Accepted Answer

We can use the equation for the location of bright fringes in a double slit experiment:

d sinθ = mλ

where d is the distance between the two slits, θ is the angle from the centerline to the fringe, m is the order of the fringe (0, 1, 2, etc.), and λ is the wavelength of the light.

We are given d = 6.00 μm, θ = 32.3°, and m = 5. Solving for λ:

λ = d sinθ / m

λ = (6.00 × 10^-6 m) sin(32.3°) / 5

λ = 6.41 × 10^-7 m = 641 nm

Therefore, the answer is D: 641 nm.

Two Thin Slits Are 6