Description : A ray of white light strikes the surface of an object. If all the colours are reflected, the surface would appear (1) Black (2) White (3) Grey (4) Opaque
Last Answer : (2) White Explanation: Objects do not have any colour of their own. When light hits a surface, some of it is absorbed and some of it is reflected. The light that is reflected is ... appear white when they reflect all the wavelengths; they appear black when they absorb all visible wavelengths.
Description : Loss due to the diffraction of light when it strikes on the irregularities formed during the manufacturing process of the fiber optics. A. Absorption loss B. Attenuation C. Bending loss D. Rayleigh scattering loss
Last Answer : D. Rayleigh scattering loss
Description : A light ray traveling from glass into air strikes the glass-air surface at an angle 50 degrees to the normal. If the critical angle for the glass-air combination is 42 degrees, the percentage of light reflected from the surface is w) 6 x) 25 y) 38 z) 100
Last Answer : ANSWER: Z -- 100
Description : When a wave strikes a vertical breakwater in deep water, it is reflected back and on meeting another advancing wave of similar amplitude merges and rises vertically in a wall of water. This phenomenon is called (A) Surf (B) Clapotis (C) Fetch (D) Swell
Last Answer : (B) Clapotis
Description : It is the angle at which the propagating ray strikes the interface with respect to the normal. ∙ A. refracted angle ∙ B. incident angle ∙ C. reflected angle ∙ D. critical angle
Last Answer : incident angle
Description : Assume light is traveling through glass, what happens when this light strikes the glass-air boundary?
Last Answer : Part of the light ray is reflected back into the glass and part of the light ray is refracted (bent) as it enters the air.
Description : Scattering losses are caused by the interaction of light with density fluctuations within a fiber. What are the two scattering mechanisms called when the size of the density fluctuations is (a) greater than and (b) less than one-tenth of the operating wavelength?
Last Answer : . (a) Mie scattering; (b) Rayleigh scattering.
Description : Reflections in many directions ∙ a. Diffuse reflection ∙ b. Diffraction ∙ c. Scattering ∙ d. Dispersion
Last Answer : a. Diffuse reflection
Description : What happens when light strikes paper for wrapping gifts?
Last Answer : it go thow it
Description : What light that strikes the following materials clear plastic aluminum foil and tissue paper?
Last Answer : What is the answer ?
Description : In fiber-to-fiber connections, Fresnel reflection is one source of coupling losses. Light is reflected back into the source fiber and is lost. What causes Fresnel reflection?
Last Answer : A step change in refractive index that occurs at fiber joints, caused by fiber separation.
Description : What condition causes a light ray to be totally reflected back into its medium of propagation?
Last Answer : Total internal reflection occurs when the angle of refraction approaches 90 degrees. This condition occurs when the angle of incidence increases to the point where no refraction is possible.
Description : A light wave enters a sheet of glass at a perfect right angle to the surface. Is the majority of the wave reflected, refracted, transmitted, or absorbed?
Last Answer : Transmitted.
Description : In Fraunhofer diffraction pattern for single slit, a central maximum is obtained when angle of diffraction q is equal to zero. What it actually indicates? A. All the diffracted rays are parallel and focused ... are diffracted by the slit in all the directions D. The rays are reflected by the slit
Last Answer : A. All the diffracted rays are parallel and focused by slit at a single point on screen
Description : Standing waves are formed when two sets of waves of equal amplitude and frequency w) are in phase x) are in opposite phase y) move through each other in opposite directions z) are reflected from the same surface
Last Answer : ANSWER: Y -- MOVE THROUGH EACH OTHER IN OPPOSITE DIRECTIONS
Description : Dispersion is used to describe the a. Splitting of white light into its component colors b. Propagation of light in straight lines c. Bending of a beam of light when it goes from one medium to another d. Bending of a beam light when it strikes a mirror
Last Answer : a. Splitting of white light into its component colors
Description : Dispersion is used to describe the ∙ a. Splitting of white light into its component colors ∙ b. Propagation of light in straight lines ∙ c. Bending of a beam of light when it goes from one medium to another ∙ d. Bending of a beam light when it strikes a mirror
Description : What do we call the piece of paper that proves you have bought the item?
Last Answer : RECEIPT
Description : The Doppler effect causes a change in what aspect of rf energy that strikes a moving object?
Last Answer : Frequency.
Description : The sun appears red at sunrise and sunset while it appears white at noon because of _____ A. Refraction B. It is cooler at sunrise and at sunset C. Diffraction leading to red end of the spectrum reaching the earth D. Scattering of light due to dust particles and air molecules
Last Answer : ANSWER: D
Description : Blue of the sky is due to the (a) Refraction of white light by the atmosphere (b) Reflection of white light by the earth (c) Scattering of white light by molecules of air (d) Interference of white light
Last Answer : Ans:(c)
Description : which of the following statements is not true for scattering of light? (a) Colour of the scattered tight depends on the size of particles of the atmosphere. (b) Red light is least scattered in the ... air scatter the blue, light more strongly than red. So the scattered blue light enters our eyes.
Last Answer : (c) Scattering of light Lakes place as various colours of white light travel with different speed in fir.
Description : The sun appears red at sunrise and sunset while it appears white at noon, because A. Of refraction B. It is cooler at sunrise and at sunset C. Of diffraction leading to red end of the spectrum reaching the earth. D. Of Scattering of light due to dust particles and air molecules?
Last Answer : C. Of diffraction leading to red end of the spectrum reaching the earth.
Description : Which radio frequency bands use the tropospheric scattering principle for propagation of radio waves?
Last Answer : Vhf and above
Description : What happens to reflected energy that enters a directional coupler that is designed to sample incident energy?
Last Answer : . The reflected energy adds at the absorbent material and is absorbed.
Description : A sound wave that is reflected back toward the source is known as what type of sound?
Last Answer : Echo.
Description : When a wave is reflected from a surface, energy is transferred. When is the transfer of energy greatest?
Last Answer : When the incident wave is nearly parallel with the surface.
Description : What factor determines whether a radio wave is reflected or refracted by the ionosphere?
Last Answer : Thickness of ionized layer.
Description : What is one of the major reasons for the fading of radio waves which have been reflected from a surface?
Last Answer : Shifting in the phase relationships of the wave.
Description : Microwaves can be focused and reflected in the same way as what other type of waves?
Last Answer : Light waves.
Description : A wavefront undergoes a phase change as it travels along the fiber. If the wavefront transverses the fiber twice and is reflected twice and the total phase change is equal to 1/2 p, will the wavefront disappear? If yes, why?
Last Answer : Yes, the wavefront will disappear because the total amount of phase collected must be an integer multiple of 2 p. (If the propagating wavefronts are out of phase, they will disappear. ... interfere with the wavefronts out of phase. This type of interference is called destructive interference.)
Description : When a wave is reflected from a surface, energy is reflected. When is the reflection of energy the greatest?
Last Answer : When the wave is nearly parallel to the reflecting surface.
Description : Two layers of arimid yarn strength members encase the OFCC units. Why are these strength members stranded in opposing directions?
Last Answer : To minimize microbending of the fibers.
Description : What type of antenna radiates in and receives energy from all directions at once?
Last Answer : Omnidirectional.
Description : In a dc motor that must be able to rotate in both directions, how is the direction changed?
Last Answer : By reversing either field or armature connections
Description : The parasitic array can be rotated to receive or transmit in different directions. What is the name given to such an antenna?
Last Answer : Rotary array.
Description : A radiating source that radiates energy equally in all directions is known as what type of radiator?
Last Answer : Isotropic radiator.
Description : Two methods describe how light propagates along an optical fiber. These methods define two theories of light propagation. What do we call these two theories?
Last Answer : The ray theory and the mode theory.
Description : When light strikes materialsit passes through thembut it is scattered from its straight parth?
Last Answer : Need answer
Description : What light makes an apple red when it strikes it?
Last Answer : Any full spectrum light such as suns light will the color of theapple appear red. Any partial spectrum light which contains redwill also work. This result is due to the refection of red light bythe pigments in the apple's skin. All other colours areabsorbed.
Description : When light strikes an opaque material accurately describes what happens to the light rays?
Description : When light strikes perpendicular to the surface of a pane og glass how much light is reflcted and how much is transmitted at the firts surface?
Last Answer : Only about 4% is reflected, the rest is transmitted. 3. (29.1) When light strikes perpendicular to the surface of a pane of glass, how much light is reflected and how much is transmitted? Normal to the surface refers to a line that is drawn perpendicular to the surface (90°).
Description : When light strikes perpendicular to the surface of a pane of glass, how much light is rflected and how much is transmitted at the first surface?
Last Answer : It reverses direction and goes back through the original medium;part goes into the second medium.
Description : Total internal reflection takes place if the light ray strikes the interface at an angle with what relationship to the critical angle? a. Less than b. Grater than c. Equal to d. Zero
Last Answer : b. Grater than
Description : How do you reduce the loss that is produced when light strikes a flat polished end of a fiber optic? A. By painting the surface B. By inclining the surface C. By cooling D. By application of antireflection coating
Last Answer : D. By application of antireflection coating
Description : Total internal reflection takes place if the light ray strikes the interface at an angle with what relationship to the critical angle? ∙ A. less than ∙ B. greater than ∙ C. equal to ∙ D. zero
Last Answer : ∙ B. greater than
Description : When light strikes a flat polished end of a fiber, the fiber loss produced can be reduced by ∙ a. Splicing ∙ b. Antireflection coating ∙ c. Insulation jacket ∙ d. All of these
Last Answer : ∙ b. Antireflection coating
Description : When light strikes a flat polished end of a fiber, it produces a loss of ∙ a. 14 % ∙ b. 4 % ∙ c. 10 % ∙ d. 1 %
Last Answer : ∙ b. 4 %
Description : Total internal reflection takes place if the light ray strikes the interface at an angle with what relationship to the critical angle? ∙ a. Less than ∙ b. Grater than ∙ c. Equal to ∙ d. Zer
Last Answer : ∙ b. Grater than
Description : A light ray traveling in benzene strikes the benzene-air surface at the critical angle. The angle of refraction of the light ray is: w) 30 degrees x) 60 degrees y) 90 degrees z) 180 degrees
Last Answer : ANSWER: Y -- 90 DEGREES