Single Slit The slit width is a=0.04 mm. The laser light wavelength is 650 nm. For small angles, in Equation 1,sinθ≈tanθ=x/l (the small angle approximation). l is the distance between the slit wheel and the mask on the front of the light sensor. Open Diffraction_Data.cap file. In the Diffraction and Interference graph window, choose Run \#1 pressing the Data △. button to obtain the data recorded during the experiment. (a) Measure the distance x between the central maximum and the first diffraction minimum for the single slit. Click the Show data coordinates and access Delta Tool button % on the upper panel of the graph window. Right click the cursor. Press Show Delta Tool. Using this tool measure the distance between the first minima on each side of the central maximum and divide by two. Record this value of x to your report file.