In part B of the experiment a Michelson Interferometer is used to determine the wavelength λ of the laser. An interference pattern is observed due to the light being split into two paths with slightly different lengths.A vacuum chamber (of length d) is placed in one of the paths and the air pumped out. Then as air leaks back into the chamber the number of fringes, N, that pass a certain point are counted as the interference pattern changes.The following measurements were taken:N= 64 ± 5d= (0.077 ± 0.006) mThe wavelength λ of the laser is calculated to be 650 nm (using the value of the refractive index of air n given in the lab manual). Calculate the uncertainty of the wavelength λ of the laser in nm to the nearest whole number.

In part A of the experiment a pair of slits are illuminated with a laser and an interference pattern is observed. The slit spacing is d = 0.0001 m and the pattern is projected on to the wall a distance L= 2.35 m from the slits. From one dark spot 7 further dark spots are counted and the distance is measured to be Z = 0.093 m.Calculate the wavelength λ of the laser.

If light illuminates a double slit an interference pattern of alternating bright and dark spots is seen. The intensity of the bright spots is brighter at the centre due to the width of the slits. The bright interference fringes will be readily observed inside the broad central diffraction maximum. Outside this they will be much fainter.A laser of wavelength λ = 650 nm is shone on a pair of slits each of width a = 18 µm. The slit spacing is d = 0.1 mm. The resulting interference pattern is projected on to a screen a distance L= 2.6 m from the double slit.Counting out from the (n= 0) central bright interference fringe, how many more bright interference fringes will be seen before the intensity drops to zero at the edge of the central diffraction maximum.Express your answer to the nearest whole number.

In part A of the experiment a pair of slits are illuminated with a laser and an interference pattern is observed. The slit spacing is d = (0.100 ± 0.003) mm and the pattern is projected on to the wall a distance L= (2.352 ± 0.019) m from the slits. From a dark spot 8 further dark spots are counted and the distance is measured to be Z = (12.2 ± 0.1) cm.The wavelength of the laser is calculated to be λ = 648 nm.Calculate the uncertainty in the wavelength. Express answer in nm (1x10-9m) to the nearest whole number.

f light illuminates a double slit an interference pattern of alternating bright and dark spots is seen. The intensity of the bright spots is brighter at the centre due to the width of the slits. The bright interference fringes will be readily observed inside the broad central diffraction maximum. Outside this they will be much fainter.A laser of wavelength λ = 650 nm is shone on a pair of slits each of width a = 17 µm. The slit spacing is d = 0.2 mm. The resulting interference pattern is projected on to a screen a distance L= 2.6 m from the double slit.Counting out from the (n= 0) central bright interference fringe, how many more bright interference fringes will be seen before the intensity drops to zero at the edge of the central diffraction maximum.Express your answer to the nearest whole number.

In part A of the experiment a hair is illuminated with a laser and a diffraction pattern is observed. The wavelength λ = (648 ± 24) nm and the pattern is projected on to the wall a distance L = (2.226 ± 0.006) m from the hair. The distance across the central maximum is measured to be 2y= (0.048 ± 0.003) m.The width of the hair is calculated to be a= 60.1 µmCalculate the uncertainty in the width of the hair Δa in µm, to one decimal place.