Physics Question!!

Question

In a double slit experiment the first minimum for 420 m violet light is at an angle of 49°.

delta = 420nm

angle = 49 degrees

Find the distance between the two slits in micrometers.

Answer 1

The condition for the first minimum is

dsinθ = λ/2 (the two waves are out of phase by 180°, so they cancel out at that spot)

You know λ = 420nm and θ = 49°. Solve the equation for the distance between the slits d.

I hope this helps.