In part 6.2.2, you will determine the wavelength of the laser by shining the laser beam on a "diffraction grating", a set of regularly spaced lines. suppose the pattern is displayed on a screen a distance l from the grating and the spots are separated by s. if the screen is 11 m away, the spots are 4.5 cm apart, and the lines of the grating are separated by 0.5 mm, what is λ (mm)?

λ = 2042 nm

Explanation:

given data

screen distance d = 11 m

spot s = 4.5 cm = 4.5 × m

separation L = 0.5 mm = 0.5 × m

to find out

what is λ

solution

we will find first angle between first max and central bright

that is tan θ = s/d

tan θ = 4.5 ×  / 11

θ = 0.234

and we know diffraction grating for max

L sinθ  = mλ

here we know m = 1  so put all value and find λ

L sinθ  = mλ

0.5 ×  sin(0.234)  = 1 λ

λ = 2042.02 ×  m

λ = 2042 nm

like poles repel so keep pushing north to north and repels funny to see this