What is the wavelength in nm of a light whose first order bright band forms a
diffraction angle of 30 degrees, and the diffraction grating has 700 lines per
mm? (give answer in whole number format) *
Your answer

714 nm

Explanation:

Using the equation: nλ=dsinθ

where

n= order of maximum

λ= wavelength

d= distance between lines on diffraction grating

θ= angle

n is 1 because the problem states the light forms 1st order bright band

λ is unknown

d=   or 0.0000014 (meters)

sin(30)= 0.5

so

(1)λ=(0.0000014)(0.5)

=0.000000714m or 714 nm