Description : An Electromagnetic wave falls on to a boundary between two losses less homogeneous media with different refractive indices, a part of the wave is reflected back to the incident medium and the rest is transmitted ... A) Fresnel reflection (B) Fresnel refraction (C) Snell's law (D) None of these
Last Answer : Answer: Option A
Description : Reduction of Fresnel reflection is possible by reducing the step change in the refractive index at the fiber interface. What material reduces the step change in refractive index at a fiber interface?
Last Answer : Index matching gel.
Description : How are source-to-fiber coupling and microbending and macrobending losses affected by changes in core diameter and D?
Last Answer : Coupling efficiency increases with both core diameter and D, while bending losses increase directly with core diameter and inversely with D.
Description : Fiber-to-fiber coupling loss is affected by intrinsic and extrinsic coupling losses. Can intrinsic coupling losses be limited by limiting fiber mismatches?
Last Answer : Yes.
Description : What do you call the reflection of a part of incident light at the interface of two media that have different refractive indices? A. Snell’s reflection B. Fresnel reflection C. Lambertian reflection D. Huygen’s reflection
Last Answer : B. Fresnel reflection
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 : The dominant loss mechanisms in silica fiber are ∙ a. Absorption and radiation losses ∙ b. Absorption and Rayleigh scattering ∙ c. Coupling and radiation losses ∙ d. Radiation and modal dispersion
Last Answer : b. Absorption and Rayleigh scattering
Description : When the clearance above the obstruction is equal to the radii of even Fresnel zone at the point of reflection the RSL A. remains the same B. is above threshold C. is decreased D. is increased
Last Answer : C. is decreased
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 : 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 : In Fresnel diffraction A. source of light is kept at infinite distance from the aperture B. source of light is kept at finite distance from the aperture C. Convex lens used D. aperture width is selected so that it can acts as a point source
Last Answer : B. source of light is kept at finite distance from the aperture
Description : A sound wave that is reflected back toward the source is known as what type of sound?
Last Answer : Echo.
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 : Is coupling loss from fiber separation and lateral misalignment more critical in expanded-beam or butt-jointed connectors?
Last Answer : Butt-jointed connectors.
Description : Does coupling loss from refractive index profile difference result when the receiving fiber has a larger profile parameter
Last Answer : Fiber alignment.
Description : What is the basic fiber cleaving technique for preparing optical fibers for coupling?
Last Answer : Score-and-break.
Description : How does index matching gel affect the amount of coupling loss caused by (a) fiber separation, (b) lateral misalignment, and (c) angular misalignment?
Last Answer : (a) Reduces coupling loss, (b) does not change coupling loss, and (c) increases coupling loss
Description : What connection properties result in fiber optic connector coupling loss?
Last Answer : Poor fiber alignment and end preparation, fiber mismatches, and Fresnel reflection.
Description : Will fiber coupling loss generally increase or decrease if the mode field diameter of a single mode fiber is decreased?
Last Answer : Increase.
Description : As the core and cladding modes travel along the fiber, mode coupling occurs. What is mode coupling?
Last Answer : Mode coupling is the exchange of power between two modes.
Description : How is fiber sensitivity to bending losses reduced?
Last Answer : Fiber sensitivity to bending losses can be reduced if the refractive index of the core is increased and/or if the overall diameter of the fiber increases.
Description : What does the law of reflection tell us about the angle of a reflected ray of light?
Last Answer : The law of reflection states that a light ray will reflect at the same angle that it hits a surface. We can use this law to guide light to different targets!
Description : When a light wave suffers reflection at the interface between air and glass medium, the change of wavelength of the reflected wave in air is equal to (a) 0 (b) λ/2 (c) λ (d) 2λ
Last Answer : (b) λ/2
Description : When a light wave suffers reflection at the interface between air and glass medium, the change of phase of the reflected wave in air is equal to (a) 0 (b) π (c) 2π (d) π/2
Last Answer : (b) π
Description : When a light wave suffers reflection at the interface between air and glass medium, the change of phase of the reflected wave in air is equal to A. 0 B. π C.2 π D.π /2
Last Answer : B. π
Description : When light is reflected from a surface, the angle of incidence is: w) 30 degrees x) equal to the angle of reflection y) 90 degrees z) 180 degrees
Last Answer : ANSWER: X -- EQUAL TO THE ANGLE OF REFLECTION
Description : What are the main causes of coupling loss?
Last Answer : Poor fiber end preparation and poor fiber alignment.
Description : Which of the following statement(s) is/are true concerning protein/amino acid metabolism in man? a. The major source of amino acids is breakdown of circulating proteins b. The recommended daily ... balance refers to a decrease in nitrogen taken into the body versus the amount of nitrogen lost
Last Answer : Answer: b, d About 15% of the total body weight is made up of proteins, about half of which are intracellular and half extracellular. In man and other animals, dietary protein is the source of ... is exceeded by the amount of nitrogen lost in the urine, stool, skin, wounds, and fistula drainage
Description : Modes of a light pulse that enter the fiber at one time exit the fiber at different times. This condition causes the light pulse to spread. What is this condition called?
Last Answer : Modal dispersion.
Description : When connector losses, splice losses and coupler losses are added, what is the limiting factor? ∙ A. source power ∙ B. fiber attenuation ∙ C. connector and splice loss ∙ D. detector sensitivity
Last Answer : D. detector sensitivity
Description : When connectorlosses,splice losses, and couplerlosses are added,whatisthe finallimitingfactor? a. Source power b. Fiber attenuation c. Connector and splice losses d. Detector sensitivity
Last Answer : d. Detector sensitivity
Description : When light strikes a piece of white paper, the light is reflected in all directions. What do we call this scattering of light?
Last Answer : Diffusion.
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 : When a student can no longer recall material he had learned some time back, one can assume that Options: A) He had never learned it B) He repressed it C) It was lost as a result of the interference of subsequent leanings D) The neural connections involved faded as a result of disuse
Last Answer : C) It was lost as a result of the interference of subsequent leanings
Description : What causes copper losses?
Last Answer : Resistance in the armature coils, which increases with temperature
Description : Why are visible-light LEDs not used for fiber optics? ∙ a. It has high losses ∙ b. It has short wave ∙ c. It has low attenuation ∙ d. It has weak signal
Last Answer : ∙ a. It has high losses
Description : Find the reflection coefficient of a wave with an incident electric field of 5 units and reflected electric field of 2 units. a) 2.5 b) 0.4 c) 0.8 d) 1.2
Last Answer : b) 0.4
Description : A wave incident on a surface at an angle 60 degree is having field intensity of 6 units. The reflected wave is at an angle of 30 degree. Find the field intensity after reflection. a) 9.4 b) 8.4 c) 10.4 d) 7.4
Last Answer : c) 10.4
Description : a) For a transmission line, Find SWR and reflection coefficient R if, i. There is no reflected voltage. ii. Reflected voltage and incident voltage is equal. iii. If reflected voltage=20V and incident voltage=10V. iv. If reflected voltage=10V and incident voltage =20V.
Last Answer : reflection coefficient R=Vr/Vi i. There is no reflected voltage. i.e,Vr=0 R=0 SWR= 1+R/1-R=1 ii. Reflected voltage and incident voltage is equal. Vr=Vi; R=1 SWR= 1+R/1-R=1+1/1-1=infinity iii. If reflected ... and incident voltage =20V. Vr=10 and Vi=20 R=10/20=0.5 SWR= 1+R/1-R=1+.5/1-.5=3
Description : What is a specific path the light takes in an optical fiber corresponding to a certain angle and number of reflection a. Mode b. Grade c. Numerical Aperture d. Dispersion
Last Answer : a. Mode
Description : Light traveling in optical fiber follows which of the following principles. ∙ a. Huygen’s principle ∙ b. Reflection theory ∙ c. Light theory ∙ d. Snell’s law
Last Answer : d. Snell’s law
Description : What is a specific path the light takes in an optical fiber corresponding to a certain angle and number of reflection ∙ a. Mode ∙ b. Grade ∙ c. Numerical Aperture ∙ d. Dispersion
Description : Optical fiber uses reflection to guide light through a channel, in which angle of incidence is ................. the critical angle. (A) equal to (B) less than (C) greater than (D) less than or equal to
Last Answer : (C) greater than
Description : Fiber optics cable used in communication, works on the principle of (1) regular reflection of light (2) diffuse reflection of light (3) refraction of light (4) total internal reflection of light
Last Answer : total internal reflection of light
Description : Delay differences between the source wavelengths occur as the optical signal propagates along the fiber. What is this called?
Last Answer : Differential group delay t(l).
Description : Light propagates in multimode graded-index fibers according to refraction and total internal reflection. When does total internal reflection occur?
Last Answer : When the angle of incidence becomes larger than the critical angle of incidence.
Description : Loose or inefficient coupling of energy into or out of a waveguide can be accomplished by the use of what method?
Last Answer : Slots and apertures.
Description : What are the main causes of absorption in optical fiber?
Last Answer : Intrinsic and extrinsic material properties.
Description : Good connections are more critical with ____________________-mode fiber.
Last Answer : single
Description : What connections in a TDR system are reversed to set up the system for addition?
Last Answer : . The R1 and R3 leads between the TDR rotor and the TX to which it is connected.