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Optical Phenomena


Problems on Interference

Problem : What is the amplitude of the magnetic field of a light ray that has an irradiance of 0.00003 W/cm 2 .


Problem : What is the position of the fourth maximum for a double-slit apparatus with slits 0.05 centimeters apart and a screen 1.5 meters distant when performed with monochromatic red light of frequency 384×1012 Hz?


Problem : In a Young's Double Slit experiment, what is the ratio of the irradiance at a distance 1 centimeter from the center of the pattern, irradiance of each individual beam entering through the slits (assume the same set up as before: light of frequency 384×1012 Hz, 0.05 centimeters between the slits, and a screen 1.5 meters away)?


Problem : A stream of electrons, each having an energy 0.5 eV is incident on two extremely thin slits 10 -2 millimeters apart. What is the distance between adjacent minima on a screen 25 meters behind the slits ( m e = 9.11×10-31 kilograms, and 1eV = 1.6×10-19 Joules). Hint: use de Broglie's formula, p = h/λ to find the wavelength of the electrons.


Problem : A Michelson interferometer can be used to calculate the wavelength of light by moving on of the mirrors and observing the number of fringes that move past a particular point. If a displacement of the mirror by λ/2 causes each fringe to move to the position of an adjacent fringe, calculate the wavelength of light being used if 92 fringe pairs pass a point when the mirror is shifted 2.53×10-5 meters.