Description : The first laser emitted ∙ a. Pulses of 694 nm red light ∙ b. A continuous red beam ∙ c. Pulses of white light from a helical flash lamp ∙ d. Spontaneous emission
Last Answer : ∙ a. Pulses of 694 nm red light
Description : Infrared light has a wavelength that is ∙ A. less than 400 nm ∙ B. more than 700 nm ∙ C. less than 700 nm ∙ D. a little over 400 nm
Last Answer : B. more than 700 nm
Description : ange of wavelength of visible light ∙ A. 670 nm to 10^3 nm ∙ B. 440 nm to 540 nm ∙ C. 110 nm to 240 nm ∙ D. 390 nm to 770 nm
Last Answer : D. 390 nm to 770 nm
Description : The wavelength of visible light extends from ∙ a. 0.8 to 1.0 nm ∙ b. 400 to 750 nm ∙ c. 200 to 660 nm ∙ d. 700 to 1200 nm
Last Answer : b. 400 to 750 nm
Description : The laser frequency when the light has the wavelength 800 nm is ∙ a. 375 x 1012 Hz ∙ b. 475 x 1015 Hz ∙ c. 375 x 109 Hz ∙ d. 375 x 1018 Hz
Last Answer : d. 375 x 1018 Hz
Description : Light rays that are emitted simultaneously from an LED and propagated down an optical fiber do not arrive at the far end of the fiber at the same time results to ∙ A. intramodal dispersion ∙ B. pulse length dispersion ∙ C. modal dispersion ∙ D. wavelength dispersion
Last Answer : D. wavelength dispersion
Description : The wavelength of a visible extends from ∙ A. 0.8 to 1.6 um ∙ B. 400 to 750 nm ∙ C. 200 to 660 nm ∙ D. 700 to 1200 nm
Last Answer : B. 400 to 750 nm
Description : How many modes possible with a multimode step-index with a core diameter of 50 um, a core refractive index of 1.6, a cladding refractive index of 1.584, and a wavelength of 1300 nm. ∙ A. 456 ∙ B. 213 ∙ C. 145 ∙ D. 372
Last Answer : D. 372
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 : Both LEDs and ILDs operate correctly with ∙ A. forward bias ∙ B. reverse bias ∙ C. neither forward nor reverse bias ∙ D. either forward or reverse bias
Last Answer : A. forward bias
Description : Both LEDs and ILDs operate correctly with ∙ a. Forward bias ∙ b. Reverse bias ∙ c. Neither A or B ∙ d. Either A or B
Last Answer : a. Forward bias
Description : What is the lifetime of LEDs? ∙ a. 200,000 minutes ∙ b. 200,000 hours ∙ c. 150,000 minutes ∙ d. 150,000 hours
Last Answer : a. 200,000 minutes
Description : Which laser emits light in the visible range 400 to 700 nm? ∙ a. Argon-ion ∙ b. Nitrogen ∙ c. Carbon-dioxide ∙ d. Neodymium-YAG
Last Answer : a. Argon-ion
Description : The law that states “When visible light of high frequency electromagnetic radiation illuminates a metallic surface, electrons are emitted” is known as ____________. ∙ A. Einstein law of photon ∙ B. Marconi’s law ∙ C. Maxwell’s law ∙ D. Plank’s law
Last Answer : D. Plank’s law
Description : Is the width of the range of wavelengths emitted by the light source ∙ a. Bandwidth ∙ b. Chromatic Dispersion ∙ c. Spectral width ∙ d. Beamwidth
Last Answer : c. Spectral width
Description : What is the spectral width of an ILD? ∙ A. 0.1 nm to 1 nm ∙ B. 2 nm to 5 nm ∙ C. 1 nm to 3 nm ∙ D. 3 nm to 4 nm
Last Answer : C. 1 nm to 3 nm
Description : What is the spectral width of a standard LED? ∙ A. 20 to 40 nm ∙ B. 30 to 50 nm ∙ C. 10 to 30 nm ∙ D. 40 to 60 nm
Last Answer : 30 to 50 nm
Description : Range of wavelengths of ultraviolet ∙ A. 670 nm to 10^3 nm ∙ B. 440 nm to 540 nm ∙ C. 110 nm to 240 nm ∙ D. 10 nm to 390 nm
Last Answer : D. 10 nm to 390 nm
Description : Range of infrared ∙ A. 360 nm to 440 nm ∙ B. 670 nm to 10^3 nm ∙ C. 110 nm to 240 nm ∙ D. 770 nm to 10^6 nm
Last Answer : D. 770 nm to 10^6 nm
Description : The graded-index multimode optical fiber has a core diameter of _____ nm. ∙ a. 0.5 ∙ b. 0.05 ∙ c. 0.0005 ∙ d. 5
Last Answer : ∙ a. 0.5
Description : A step-index multimode optical fiber has a core diameter of _____ nm. ∙ a. 0.02 ∙ b. 0.2 ∙ c. 2 ∙ d. 0.002
Last Answer : b. 0.2
Description : A single mode optical fiber has a core diameter of _____ nm. ∙ a. 0.1 ∙ b. 0.01 ∙ c. 0.2 ∙ d. 0.05
Last Answer : a. 0.1
Description : Infrared range for fiber optics ∙ a. 400 – 700 nm ∙ b. 700 – 1200 nm ∙ c. 300 – 2000 nm ∙ d. 400 – 7000 nm
Last Answer : b. 700 – 1200 nm
Description : A popular light wavelength fiber-optic cable is ∙ A. 0.7 micrometer ∙ B. 1.3 micrometer ∙ C. 1.5 micrometer ∙ D. 1.8 micrometer
Last Answer : B. 1.3 micrometer
Description : The higher the index number ∙ A. the higher the speed of light ∙ B. the lower the speed of light ∙ C. has no effect on the speed of light ∙ D. the shorter the wavelength propagation
Last Answer : B. the lower the speed of light
Description : Which of the following terms best describes the reason that light is refracted at different angles? ∙ A. Photon energy changes with wavelength ∙ B. Light is refracted as a function of surface smoothness ∙ ... determined partly by a and b ∙ D. The angle is determined by the index of the materials
Last Answer : ∙ D. The angle is determined by the index of the materials
Description : What is the unit of light wavelength? ∙ a. Micrometer ∙ b. Angstroms ∙ c. Mils ∙ d. Fathom
Last Answer : ∙ b. Angstroms
Description : What parameter of light detector determines the range or system length that can be achieved for a given wavelength? ∙ a. Transit time ∙ b. Spectral response ∙ c. Dark current ∙ d. Responsitivity
Last Answer : ∙ b. Spectral response
Description : A popular light wavelength in fiber-optic cable is ∙ a. 0.7 um ∙ b. 1.3 um ∙ c. 1.5 um ∙ d. 1.8 um
Last Answer : b. 1.3 um
Description : ______ dispersion is caused by the difference in the propagation times of light rays that take different paths down a fiber. ∙ a. Material dispersion ∙ b. Wavelength dispersion ∙ c. Modal dispersion
Last Answer : ∙ c. Modal dispersion
Description : The wavelength of light has no role in ∙ a. Diffraction ∙ b. Interference ∙ c. Polarization ∙ d. Reflection
Last Answer : c. Polarization
Description : When a beam of light enters one medium from another, which quantity will not change? ∙ a. Direction ∙ b. Speed ∙ c. Frequency ∙ d. Wavelength
Last Answer : c. Frequency
Description : Is the different angle of entry of light into an optical fiber when the diameter of the core is many times the wavelength of the light transmitted. ∙ a. Acceptance angle ∙ b. Modes ∙ c. Sensors ∙ d. Aperture
Last Answer : b. Modes
Description : Which color has the shortest wavelength of light? ∙ a. Red ∙ b. Yellow ∙ c. Blue ∙ d. Green
Last Answer : c. Blue
Description : The _____ is equal to the number of electrons emitted per second times the electron charge ∙ a. Intensity ∙ b. Optical power ∙ c. Photocurrent ∙ d. Responsitivity
Last Answer : c. Photocurrent
Description : Which is the proper measurement of average power emitted by a pulsed laser? ∙ a. Energy x time ∙ b. Pulse energy x repetition rate ∙ c. Pulse energy / repetition rate ∙ d. Peak power x pulse length
Last Answer : ∙ b. Pulse energy x repetition rate
Description : The range of wavelength values that a given photodiode will respond. ∙ A. spectral response ∙ B. permeance ∙ C. dark current ∙ D. reluctance
Last Answer : A. spectral response
Description : The bandwidth of a fiber is limited by ∙ a. Mode ∙ b. Wavelength ∙ c. Dispersion ∙ d. Frequency
Last Answer : c. Dispersion
Description : Modal dispersion is caused by the ∙ a. Dependence of wavelength on index of refraction ∙ b. Dependence of propagation constant on index of refraction ∙ c. Dependence of the propagation constant on the wavelength ∙ d. Dependence of the propagation constant on the mode number
Last Answer : d. Dependence of the propagation constant on the mode number
Description : Material dispersion is caused by the ∙ a. Wavelength dependence of the index of refraction ∙ b. Wavelength independence of the index of refraction ∙ c. Dependence of the propagation constant on the mode number ∙ d. Independence of the propagation constant on the mode number
Last Answer : d. Independence of the propagation constant on the mode number
Description : If six men working 8 hours a day earn Rs.840 per week, then 9 men working 6 hours per day will earn per week a) Rs. 940 b) Rs. 945 c) Rs. 1620 d) Rs. 1680 e) Rs. 1245
Last Answer : b) Rs. 945
Description : X invested three- nineth, Y invested three-seventh of the remaining and Zth remaining. If Y earned Rs.840 as profit pr each year. Find the average monthly profit of all. A) 510 B) 490 C) 630 D) 370
Last Answer : Answer: B) Let total amount puts by X, Y& Z be P X's investment = 3/9 P Balance investment =6/9 p Y's investment =6/9*P*3/7=2/7 P Remaining investment =8 p/21 =Z's amounts Profit ratio ... :6:8 1month share =840/12=Rs .70 Average monthly profit of X, Y, Z=70/3 *21 =Rs.490
Description : LASER stands for: a. Light Amplification by Simulated Emission of Radiation b. Light Amplification by Stimulated Emission of Radiation c. Light Amplification by Simulated Emitted Rays d. Light Amplification by Stimulated Emitted Rays
Last Answer : b. Light Amplification by Stimulated Emission of Radiation
Description : Refraction is the ∙ A. bending of light ∙ B. reflection of light waves ∙ C. distortion of light waves ∙ D. diffusion of light waves
Last Answer : A. bending of light
Description : The main benefit of light wave communications over microwaves or any other communications media are ∙ A. lower cost ∙ B. better security ∙ C. wider bandwidth ∙ D. freedom from interface
Last Answer : C. wider bandwidth
Description : EMD is best described by which statement? ∙ A. 70 percent of the core diameter and 70% of the fiber NA should be filled with light. ∙ B. 70 percent of the fiber diameter and 70% of the ... be measured at the output. ∙ D. 70 percent of the unwanted wavelengths should be attenuated by the fiber.
Last Answer : 70 percent of the core diameter and 70% of the fiber NA should be filled with light.
Description : The speed of light in plastic compared to the speed of light in air is ∙ A. less ∙ B. more ∙ C. the same ∙ D. zero
Last Answer : A. less
Description : The upper pulse rate and information-carrying capacity of a cable is limited by ∙ A. pulse shortening ∙ B. attenuation ∙ C. light leakage ∙ D. modal dispersion
Last Answer : D. modal dispersion
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 : The minimum optical power a light detector can receive and still produce a usable electrical output signal. ∙ A. light responsivity ∙ B. light sensitivity ∙ C. light collectivity ∙ D. illumination
Last Answer : B. light sensitivity