Constructive inteference question

[freetofu]

Homework Statement

Two sources produce coherent light waves that come together at a detector located 1.50000 mm from one source and 1.50660 mm from the other. If the two waves interfere constructively, what is(are) a possible value(s) for the wavelength? Assume the light is visible light. (Select all that apply.)

629 nm 660 nm 600 nm 535 nm 300 nm

Homework Equations

(presumably)v∆L= mλ

The Attempt at a Solution

I figured ∆L/λ gave integers for 660nm, 600nm, and 300nm, but apparently those aren't the right answers

 

[vela]

Not all of those wavelengths lie in the range for visible light.

 

[freetofu]

OK, got it. Thanks!