directions: you will be doing an assignment called, "Double Slit Diffraction Activity-(R) Young's Double Slit Experiment", there will be a link at below to help you with the assignment. All other information will be below.

Link: http://vsg.quasihome.com/interfer.htm

Simulation guidance: ? Note the three variables that can be controlled: Lambda (the wavelength [color] of light, d (the spacing between the slits), and L (the distance between the slits and the screen upon which the interference pattern is projected). ? Notice that when you change the wavelength (Lambda) the color of the wave fronts and patterns on the screen changes. ? As you operate the simulation, your goal is to count the number, n, of bright bands projected upon the screen. Although counting sounds simple enough, it can be challenging as bands appear on the far edges of the screen or disappear off the edges. ? The graph (on the far right of the simulation) shows the amplitude of the interference (the intensity of the two light sources interfering). The maximum of this intensity graph marks the center of the bright bands. You can use the graph to calculate fractions of a bright band on the edges of your screen. When the two bands at the edges reach their peak, then two half bands have joined the other bright bands in the middle of the screen. Using fractional bands at the fringes of your screen will let you calculate a more accurate n value.

Questions:

Part 1 - Varying Wavelength Procedure: 1 . Choose a slit distance and screen distance, these should remain constant for the rest of this part of the investigation. Change wavelength within the wavelength range and count the number of bright bands. (2 pts) d = (mm) L = (m) Wavelength Range Wavelength (2) chosen # of Bright bands observed 380-440 440-500 500-560 560-620 620-680 680-760 a) What is the trend for wavelength (2) and the number of bright bands? (Circle your responses) (2 pts) As wavelength ()) increases / decreases, the number of bright bands increases / decreases. b) Is it a direct or inverse relationship? (Circle the correct response) (1 pt) Direct Inverse2= (nm) L= (m) Slit Distance Range Slit distance (d) chosen # of Bright bands observed 2-2.5 mm 2.5-3.0 mm 3.0-3.5 mm 3.5-4.0 mm 4.0-4.5 mm 4.5-5.0 mm a) What is the trend for slit distance (d) and the number of bright bands? (Circle your responses) (2 pts) As slit distance (d) increases / decreases, the number of bright bands increases / decreases. b) Is it a direct or inverse relationship? (Circle the correct response) (1 pt) Direct InversePart 3 - Varying Screen Distance 3. Choose a slit distance and a wavelength, these should remain constant for the rest of this part of the investigation. Change screen distance within the specified range and count the number of bright bands. (2 pts) d = (mm) 2= (nm)Screen Distance Range Screen distance (L) chosen #- of Bright bands observed 2.0-2.5 tn a) 'What is the trend for screen distance (L) and the number of bright bands? (Circle your responses) (2 pts) As screen distance (L) increases if decreases, the number of bright bands increases f decreases. b) Is it a direct or inverse relationship? {Circle the correct response) (1 pt) Direct Inverse 4. Circle the variable(s) that are directly proportional to the number ofbands, belonging in the numerator. Wavelength (it) Slit distance (cl) Screen distance (L) (1 pts) 5. Circle the variable(s) that are inversely proportional to the number ofbands, belonging in the denominator. Wavelength (.1) Slit distance (d) Screen distance (L) (1 pts)