Week 26

Lab Report                                                                Name: ____________________

                                                                                                Section: ___________________

Diffraction Grating

  DATA TABLE:

Part 1:

Calculations:

1. Convert λ, wavelength, of laser from nm to m. Remember 1 nm = 1 x 10 ^-9 m.

1. Average all Δx values to get one Δx_avg.

1. Calculate the angle θ from tan θ = Δx_avg/L.

1. Find sin θ.

1. Solve for d using n λ = d sin θ; i.e. d = n λ/sin θ.

1. Use d to find d^-1, i.e. how many lines there are per mm of diffraction grating.

Part 2:

Calculate theta:  tan^-1 (average distance between dots on wall) / (distance from       

     card to wall)

Calculate d:  wavelength / sin theta

Calculate number of grooves per mm: 1/d

Calculate number of grooves on CD = (grooves /mm) (radius of CD- grooved part

     only)