1. A circular table of radius I m is illuminated by a mono-chromatic LED light source placed at a distance y = 2 m above the table. The wavelength and radiant power of the LED are 632 nm and 100 mW respectively. Calculate the illumination in lux of LED at the center and at the edge of the table. (Assume that the LED behaves like a point light source). LED 1m E, (center)- E, (edge) -

1. A circular table of radius I m is illuminated by a mono-chromatic LED light source placed at a distance y = 2 m above the table. The wavelength and radiant power of the LED are 632 nm and 100 mW respectively. Calculate the illumination in lux of LED at the center and at the edge of the table. (Assume that the LED behaves like a point light source). LED 1m E, (center)- E, (edge) -

Physics for Scientists and Engineers, Technology Update (No access codes included)

9th Edition

ISBN:9781305116399

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter38: Diffraction Patterns And Polarization

Section: Chapter Questions

Problem 38.15P: The angular resolution of a radio telescope is to be 0.100 when the incident waves have a wavelength...

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An electric current through hydrogen gas produces several distinct wavelengths of visible light. What are the wavelengths of the hydrogen spectrum, if they form first-order maxima at angles 24.2°, 25.7°, 29.1°, and 41.0° when projected on a diffraction grating having 10,000 lines per centimeter?
The angular resolution of a radio telescope is to be 0.100 when the incident waves have a wavelength of 3.00 mm. What minimum diameter is required for the telescopes receiving dish?
To save money on making military aircraft invisible to radar, an inventor decides to coat them with a nonreflective material having an index of refraction of 1.20, which is between that of air and the surface of the plane. This, he reasons, should be much cheaper than designing Stealth bombers. (a) What thickness should the coating be to inhibit the reflection of 4.00-cm wavelength radar? (b) What is unreasonable about this result? (c) Which assumptions are unreasonable or inconsistent?
(a) What is the minimum angular spread of a 633-nm wavelength He-Ne laser beam that is originally 1.00 mm in diameter? (b) If this laser is aimed at a mountain cliff 15.0 km away, how big will the illuminated spot be? (c) How big a spot would be illuminated on the Moon, neglecting atmospheric effects? (This might be done to hit a corner reflector to measure the round-trip time and, hence, distance.) Explicitly show how you follow the steps in Problem-Solving Strategies for Wave Optics.
A horizontal laser beam of wavelength 632.8 nm has a circular cross section 2.00 nun in diameter. A rectangular aperture is to lie placed in the center of the beam so that when the light falls perpendicularly on a wall 4.50 m away, the central maximum fills a rectangle 110 mm wide and 6.00 mm high. The dimensions are measured between the minima bracketing the central maximum. Find the required (a) width and (b) height of the aperture. (c) Is the longer dimension of the central bright patch in the diffraction pattern horizontal or vertical? (d) Is the longer dimension of the aperture horizontal or vertical? (e) Explain the relationship between these two rectangles, using a diagram.
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1. A floodlight emitting 25,000 candelas in the center of its beam is aimed at 60 degrees to a point on the ground 20 m away. What is the illuminance of the point in lux? 2. A room measuring 40ft by 80ft is to be illuminated by fluorescent lamps having an output of 3,300 lumens per lamp arranged in 4 rows. The required illuminance at the floor is 60 fc. What is the number of lamps required in each row if the luminaire efficiency is 42%?
6. The edge of a unit cell in a cubic crystal is a = 2.62 Å. Find the Bragg angle corresponding to reflection from the planes (100), (110), (111), (200) and (211), given the wavelength of the monochromatic x-ray beam is 1.54 Å.
Find the radius of a star image formed on the retina of the eye if the aperture diameter (the pupil) at night is 0.78 cm and the length of the eye is 2.3 cm. Assume the wavelength of starlight in the eye is 500 nm. (1 nm -9 10 m) O a. 2.1E-3 m O b. 1.7E–9 m c. 3.6E–6 m d. 1.8E–6 m O e. 6.4E–7 m
1. A light is to be placed directly above the center of a circular plot of radius 30 ft, at such a height that the edge of the plot will get maximum illumination. Find the height if the intensity I at any point on the edge is directly proportional to the cosine of the angle of incidence (angle between the ray of light and the vertical) and inversely proportional to the square of the distance from the source.
1) The refractive index of a lightly damped medium is given by ñ = n - ik, where the k is the extinction coefficient, Large k means that the medium is highly absorbing. a) Explain behavior of n and the reflectivity of the medium for w Wp. is the plasmon frequency of the medium. Here wp b) Zinc is a divalent metal with 6.6 x 1028 m-3 atoms per unit volume. How the zinc will appear when the EM waves of different frequencies incident on it ?
4. Two mirrors with the same power reflectivity R are utilized to form a Fabry-Perot resonator. If the separation of the two mirrors is L and the refractive index inside the resonator is n, what is the Free Spectral Range Af of the resonator in the frequency (not the angular frequency Aw) domain? Here the Free Spectral Range (FSR) is the optical frequency spacing between two successive reflected/transmit ted optical intensity maxima/minima of a resonator.