The laser light of 589 nm wavelength is shown through parallel slots?
Laser light of 589 nm wavelength is shown through parallel slits forming a series of maxima on a screen 4.20 m away. If the distance between the central maximum and the maximum first order is 1.67 cm, what is the slit separation?
The formula for the diffraction of light is λ = D sinθ / n for wavelength λ = light d = distance between the slits θ = angle produced by slits from the center to the other maxima measured. N = serial number of the term maximal (in this case, one) First, we need θ. Since the screen and the laser are at right angles to each other, we have a right triangle. Both parties are known 0.0167 m (opposite side) and 4.20 m (adjacent side). Therefore, we can use tan-1 (0.0167/4.20) to find the angle θ. It is 0.228 degrees. A quick answer as planned, due to the low ratio between the lengths of the sides. Now we can rearrange the formula for λ / sinθ = D (remember n = 1 so it does not matter in this case). Now, replace numbers and you get 589x10 ^ -9 m / sin (0.228) = 1.48 x 10 ^ -4 m, which is your answer. If you want to convert is 0.148 mm between the slits.