Double slit experiment wavelength of light used

[Iskak]

Homework Statement

Slit spacing is 0.4mm(a); fridge separation is 1.1mm(b); slit-screen distance is 0.8m(D).
Wavelength of light used is?

Relevant Equations

λ = (a*b)/D

0.8m -> 800mm
λ = (0.4mm*1.1mm)/800mm
= 0,00055mm
is it right?

I am past that 3 months ago, forgot how to solve.

 

[BvU]

Hello Iskak, $\qquad$ $\qquad$ !

https://www.physicsforums.com/threads/guidelines-for-students-and-helpers.686781/
PF isn't really for stamp-approving homework; you'll have to convince yourself it's right...

Check your notes from 3 months ago !

(Oh, and: one way to find out is to hand it in ... )