ASSIGNMENT 2

MIT–MANIPAL
PHY 102
February 2014
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
E423
2.16 m away. (b) Calculate the ratio of the intensity on the screen at a point 2.16 cm to the
E4211 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
E4217 resolved by the telescope at Mount Palomar [diameter
SP425 of the objective is 5.08 m], assuming that this distance is determined by diffraction effects. Assume a wavelength of 565 nm and the EarthMoon 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
P427 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.
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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
(400700nm)? (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
E4319 minimum number of rulings needed in a diffraction grating that can resolve these lines in
E4323 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?
6.
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X rays of