Question

You want to photograph a circular diffraction pattern whose central maximum has a diameter of 1.0 cm . You have a helium-neon laser (λ=633nm) and a 0.11-mm-diameter pinhole. Part A How far behind the pinhole should you place the viewing screen? Express your answer to two significant figures and include the appropriate units.

Answer 1

71 cm

Step-by-step explanation:

The formula to apply here is θ = 1.22λ/D,

diameter of central maximum =1.0 cm

wavelength, λ= 633 nm

Diameter of pinhole = 0.11 mm

where θ = arc length/distance = s/R

s/R = 1.22λ/D

(.005)/R = (1.22)(633 X 10^-9)/(1.1 X 10^-4)

R = .71 m which is 71 cm