Select the "Slits" simulation, and Light (green) for the type of wave. Add a barrier with two slits and a slit separation of 1750 nm, and use the tape measure as well as the slider bar below the slit to place it roughly 1300 nm away from the light source. Adjust the slit width to 300 nm, and make sure the amplitude is set to the highest setting. Which statement best describes how the intensity of the wave depends on position along the screen? A. 1. The intensity is large near the middle of the screen, then decreases to nearly zero, and then increases again as the distance from the middle of the screen increases. 2. The intensity is roughly constant 3. There are two bright bands directly in front of the slits and no light anywhere else on the screen B. Press the blue Pause button (at middle-bottom of the screen), and use the measuring tape to measure the wavelength of the green light. Now, measure the distance from the first bright fringe above the middle of the screen to the upper slit. Call this distance r2. Next, measure the corresponding distance to the lower slit, r1, as shown above. Which is true about the difference between these two distances? 1. The difference in the distances is equal to half the wavelength of the wave. 2. The difference in the distances is equal to the wavelength of the wave. 3. The difference in the distances is equal to twice the wavelength of the wave. C. Try a few other wavelengths. How does the distance between consecutive bright fringes depend on the wavelength of the light? 1. The fringes get farther apart as wavelength increases. 2. The spacing of the fringes does not change when the wavelength changes. 3. The fringes get closer together as the wavelength increases. D. Change the slit separation from 1750 nm to 3000 nm and look carefully at the screen. Wait a few seconds to see if the fringes change. How does the distance between consecutive bright fringes depend on the slit separation? 1. The fringes get farther apart as the slit separation increases. 2. The fringes get closer together as the slit separation increases 3. The distance between the fringes is not affected by the slit separation E. Now change the slit width and see what happens. Be sure to wait a few seconds to see if the fringes change. How does the distance between the bright fringes depend on the slit width (for slit widths less than the wavelength of the light)? 1. The fringes get farther apart as the slit width increases. 2. The fringes get closer together as the slit width increases 3. The distance between the fringes is not affected by the slit width F. Now change the amplitude (brightness) of the light and see what happens. Be sure to wait a few seconds to see if the fringes change. How does the distance between the bright fringes depend on the amplitude of the wave? 1. The fringes get farther apart as the amplitude increases. 2. The fringes get closer together as the amplitude increases 3. The distance between the fringes is not affected by the amplitude