Pavitra Gupta 9312281591 Pavitra Gupta 9312281591
WAVE OPTICS ( Numericals )
Q.1The refractive index of the denser media is 1.732. Calculate: (i) the polarising angle of medium. (ii) the angle of refraction at the polarising angle. [60°, 30°]
Q.2Determine the angular separation between central maximum and first order maximum of the diffraction pattern due to a single slit of width 0.25 mm, when light of wavelength 5890 Å is incident on it normally. [0.0035 radian]
Q.3In Young’s double slit experiment; the slits are separated by 0.24 mm. The screen is 1.2 m away from
the slit? The fringe width is 0.3 cm. Calculate the wavelength of light used in the experiment. [6000 Å]
Q.4Two coherent sources whose intensity ratio is 81: 1, produce interference fringes. Calculate the ratio of (i) the amplitudes of light waves (ii) intensity of maxima and minima in the fringe system. [9:1, 100:64]
Q.5 The two slits in Young’s double slit experiment are separated by a distance of 0.03 mm. An interference pattern is produced on a screen 1.5 m away. The 4th bright fringe is at a distance of 1 cm from the central maximum. Calculate the wavelength of light used. [500 Å]
Q.6InYoung’s double slit experiment, while using a source of light of wavelength 5000 Å, the fringe width obtained is 0.6 cm. If the distance between the slits and the screen is reduced to half, calculate the new fringe width. [0.3 cm]
Q.7Laser light of wavelength 630 nm incident on a pair of slits produces an interference pattern in which the bright fringes are separated by 8.1 mm. A second light produces an interference pattern in which the fringes are separated by 7.2 mm. Calculate the wavelength of the second light. [560 nm]
Q.8Consider interference between two sources of intensities I and 4I. Obtain intensity at a point where the phase difference is /2. [5 I]
Q.9In Young’s double slit experiment a light of 5000 Å is used. The third bright fringe is formed on the screen at 1 cm from central bright band. If the screen is at a distance of 1.5 m from the center of the two narrow slits, calculate the separation between the slits. [0.225 x 10-3m]
Q.10A double slit is illuminated by light of = 6000 Å. The slits are 0.1 cm apart and the screen is placed 1 m away. Calculate: (a) angular position of 10thmaxima in radian (b) separation of two adjacent minima. [0.006 radian, 0.6 mm]
Q.11The ratio of intensities of maxima and minima in an interference pattern is found to be 25 : 9. Calculate the ratio of the intensities of the sources producing this pattern. [Ans. 16: 1]
Q.12In Young’s double slit experiment; two slits are separated by 3 mm distance and illuminated by light of wavelength 480 nm. The screen is at 2 m from the plane of the slits. Calculate the separation between the 8th bright fringe and the 3rd dark fringe observed with respect to the central bright fringe. [1.76 x 10-3 m]
Q.13A ray of light falls on a transparent slab of refractive index 1.732. If reflected and refracted rays are mutually perpendicular, what is the angle of incidence?
Q.14In a Young’s double slit interference experiment, the first minima on the screen is found just in front of one of the slits when the slits are illuminated with a monochromatic source of wavelength 6000Å. If the distance of the screen from the slits is 60 cm, calculate the separation between the slits.
Q.15In Young’s double-slit experiment using monochromatic light of wavelength λ, the intensity of light at a point on the screen wherepath difference is λ, is K units. What is the intensity of light at apoint where path difference is λ/3? [K/4]
Q.16In a double-slit experiment the angular width of a fringe is found tobe 0.2° on a screen placed 1 m away. The wavelength of light used is600 nm. What will be the angular width of the fringe if the entireexperimental apparatus is immersed in water? Take refractive indexof water to be 4/3. [0.15°]
Q.17In double-slit experiment using light of wavelength 600 nm, theangular width of a fringe formed on a distant screen is 0.1º. What isthe spacing between the two slits? [3.4 × 10-4 m.]
Q.18Assume that light of wavelength 6000Å is coming froma star. What is the limit of resolution of a telescope whose objectivehas a diameter of 100 inch? [2.9 x 10-7 radian]
Pavitra Gupta 9312281591 Pavitra Gupta 9312281591