1. Monochromatic light of wavelength 441 nm falls on a narrow slit of width 25.2 μm.
(a) Find the angular positions of 1ST and 2ND minima and their linear position on a screen
2.16 m away. (b) Calculate the ratio of the intensity on the screen at a point 2.16 cm to the
E42-11 intensity at the central maximum.
2. (a) Find the angular and the linear separation of two points on the Moon’s surface that can just be
E42-17 resolved by the telescope at Mount Palomar [diameter
SP42-5 of the objective is 5.08 m], assuming that this distance is determined by diffraction effects. Assume a wavelength of 565 nm and the Earth-Moon distance is
3.84 x 108 m. (b) How far apart are the centres of diffraction pattern in the focal plane (f = 35.3m) of the lens? 3. Light of wavelength 440 nm passes through a double slit, yielding the diffraction pattern of intensity I versus
P42-7 deflection angle θ shown in figure 42.27. Calculate
(a) the slit width and (b) the slit separation. (c) Verify the displayed intensities of the m=1 and m=2 interference fringes. 4.
A diffraction grating (14.0 mm wide) has 200 rulings/mm and a principal maximum is noted at θ=28.0°. (a) What are the possible wavelengths of the incident visible light
(400-700nm)? (b) What are the values (in °/nm) of the dispersion of the grating in the vicinity of these lines?
(c) What are the values of the resolving power of this grating for these lines?
5. A source containing a mixture of hydrogen and deuterium atoms emits light containing two closely spaced red colors at λ=656.3 nm whose separation is 0.180 nm. (a) Find the
E43-19 minimum number of rulings needed in a diffraction grating that can resolve these lines in
E43-23 the first order. (b) What is the value (in °/nm) of the dispersion of the grating (14.0 mm wide) for these lines in the first order?
X rays of