Look at the bulb through the single slit in the cardboard.

Q1: How many bright fringes can you clearly see?

Q2: Manipulate the card so as to open and close the slit; what happens to the number of bright fringes as the slit is opened?

Q3: Does this agree with theory for the single slit? State the formula and explain.

Look at the bulb filament reflected off the piece of LP record and the CD. Sketch the pattern for each.  

Q4: How many bright fringes can you clearly see for the CD and the record?

Q6: Does this agree with the theory for the diffraction grating? State the formula and explain. 

.Look at the bulb and the gas discharge tube through the transmission grating (13,500 lines/in). Sketch the pattern for each.

Q7: How many bright fringes can you clearly see through the bulb.

Q8: How many orders of spectra can you clearly see for the bulb?

Q9: Does this agree with the theory for the diffraction grating? State the formula and explain.