Description : What is the lifetime of ILDs? a. 50,000 hours b. 75,000 hours c. 100,000 hours d. 125,000 hours
Last Answer : a. 50,000 hours
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 : Type of lasers that are made from semiconductor ph-junctions commonly called ILDs ∙ A. semiconductor lasers ∙ B. liquid lasers ∙ C. plasma lasers ∙ D. gas lasers
Last Answer : semiconductor lasers
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 : Which of the following cables will have the highest launch power capability? ∙ A. 50/125/0.2 ∙ B. 85/125/0.275 ∙ C. 62.5/125/0.275 ∙ D. 100/140/0.3
Last Answer : A. 50/125/0.2
Description : Lifetime of ILD’s A. 150,000 h B. 100,000 h C. 50,000 h D. 200,000 h
Last Answer : C. 50,000 h
Description : The numerical aperture of a fiber if the angle of acceptance is 15 degrees, is ∙ a. 017 ∙ b. 0.26 ∙ c. 0.50 ∙ d. 0.75
Last Answer : ∙ b. 0.26
Description : Single-mode step-index cable has a core diameter in the range of ∙ A. 100 to 1000 micrometer ∙ B. 50 to 100 micrometer ∙ C. 2 to 15 micrometer ∙ D. 5 to 20 micrometer
Last Answer : . 2 to 15 micrometer
Description : Medium 1 is a glass (n1 = 1.5) and medium 2 is an ethyl alcohol (n2 = 1.36). For an angle of incidence of 30 degrees, determine the angle of refraction. ∙ A. 44.5 degrees ∙ B. 14.56 degrees ∙ C. 33.47 degrees ∙ D. 75 degrees
Last Answer : C. 33.47 degrees
Description : The speed of light is ∙ a. 186,000 mi/h ∙ b. 300 mi/h ∙ c. 300,000 m/s ∙ d. 300,000,000 m/s
Last Answer : ∙ b. 300 mi/h
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 : 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 : What is the frequency limit of an optical fiber? ∙ a. 20 GHz ∙ b. 30 GHz ∙ c. 40 GHz ∙ d. 50 GHz
Last Answer : ∙ c. 40 GHz
Description : For a single mode optical cable with 0.25 dB/km loss, determine the optical power 100 km from a 0.1-mW light source. ∙ A. -45 dBm ∙ B. -15 dBm ∙ C. -35 dBm
Last Answer : ∙ C. -35 dBm
Description : Approximately what is the frequency limit of the optical fiber? ∙ A. 20 MHz ∙ B. 1 MHz ∙ C. 100 MHz ∙ D. 40 GHz
Last Answer : ∙ D. 40 GHz
Description : . The product of the bit rate and distance of a fiber-optic system is 2 Gbits-km/s. What is the maximum rate at 5 km? ∙ A. 100 Mbits/s ∙ B. 200 Mbits/s ∙ C. 400 Mbits/s ∙ D. 1000 Gbits/s
Last Answer : C. 400 Mbits/s
Description : The product of the bit rate and distance of a fiber-optic system is 2 Gbits km/s. What is the maximum rate at 5 km? ∙ a. 100 Mbits/s ∙ b. 200 Mbits/s ∙ c. 400 Mbits/s ∙ d. 1000 Gbits/s
Last Answer : c. 400 Mbits/s
Description : . A fiber-optic cable has a loss of 15 dB/km. The attenuation in a cable, 100 ft long is ∙ a. 4.57 dB ∙ b. 9.3 dB ∙ c. 24 dB ∙ d. 49.2 dB
Last Answer : ∙ a. 4.57 dB
Description : It refers to the abrupt of change in refractive index from core to clad ∙ A. step index ∙ B. graded index ∙ C. semi-graded index ∙ D. half step index
Last Answer : ∙ A. step index
Description : The term power budgeting refers to ∙ A. the cost of cable, connectors, equipment and installation ∙ B. the loss of power due to defective components ∙ C. the total power available minus the attenuation losses ∙ D. the comparative costs of fiber and copper installations
Last Answer : C. the total power available minus the attenuation losses
Description : Which type of fiber-optic cable is the most widely used? ∙ A. single-mode step-index ∙ B. multimode step-index ∙ C. single-mode graded index ∙ D. multimode graded index
Last Answer : B. multimode step-index
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 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 : Which of the following is not a part of the optical spectrum? ∙ A. infrared ∙ B. ultraviolet ∙ C. visible color ∙ D. x-rays
Last Answer : ∙ D. x-rays
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 : Which of the following is not a major benefit of a fiber-optic cable? ∙ A. immunity from interference ∙ B. no electrical safety problems ∙ C. excellent data security ∙ D. lower cost
Last Answer : ∙ D. lower cost
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 core of fiber-optic cable is surrounded by ∙ A. wire braid shield ∙ B. Keviar ∙ C. cladding ∙ D. plastic insulation
Last Answer : ∙ C. cladding
Description : The core of a fiber-optic cable is made of ∙ A. air ∙ B. glass ∙ C. diamond ∙ D. quartz
Last Answer : B. glass
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 : The mechanical splice is best suited for ∙ A. quicker installation under ideal condition ∙ B. minimum attenuation losses ∙ C. field service conditions ∙ D. situations in which cost of equipment is not a factor
Last Answer : D. situations in which cost of equipment is not a factor
Description : Which cable length has the highest attenuation? ∙ A. 1 km ∙ B. 2 km ∙ C. 95 ft. ∙ D. 500 ft.
Last Answer : B. 2 km
Description : Cable attenuation is usually expressed in terms of ∙ A. loss per foot ∙ B. dB/km ∙ C. intensity per mile ∙ D. voltage drop per inch
Last Answer : . dB/km
Description : Which of the following is not a common type of fiber-optic cable? ∙ A. single-mode step-index ∙ B. multimode graded-index ∙ C. single-mode graded-index ∙ D. multimode step-index
Last Answer : . single-mode graded-index
Description : The operation of a fiber-optic cable is based on the principle of ∙ A. refraction ∙ B. reflection ∙ C. dispersion ∙ D. absorption
Last Answer : A. refraction
Description : Loss comparisons between fusion splices an mechanical splices ∙ A. 1:10 ∙ B. 10:1 ∙ C. 20:1 ∙ D. 1:20
Last Answer : A. 1:10
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 : Which of the following is not a common application of fiber-optic cable? ∙ A. computer networks ∙ B. long-distance telephone system ∙ C. closed-circuit TV ∙ D. consumer TV
Last Answer : ∙ D. consumer TV
Description : Type of lasers that use solid, cylindrical crystals such as ruby ∙ A. solid lasers ∙ B. ILD ∙ C. gas lasers ∙ D. liquid lasers
Last Answer : ∙ A. solid lasers
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 : Type of lasers that use organic dyes enclosed in glass tube for an active medium. ∙ A. liquid lasers ∙ B. plasma lasers ∙ C. neon lasers ∙ D. ruby lasers
Last Answer : liquid lasers
Description : Type of lasers that uses a mixture of helium and neon enclosed in glass tube. ∙ A. gas lasers ∙ B. solid lasers ∙ C. semiconductor lasers ∙ D. liquid lasers
Last Answer : A. gas lasers
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
Description : The term responsivity as it applies to a light detector is best described as ∙ A. the time required for the signal to go from 10 to 90 percent of maximum amplitude ∙ B. the ratio of the diode ... . the ratio of the input power to output power ∙ D. the ratio of output current to input current
Last Answer : the ratio of the diode output current to the input optical power
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 time it takes a light induced carrier travel across the depletion region of the semiconductor. ∙ A. dispersion ∙ B. response time ∙ C. irradiance ∙ D. transit time
Last Answer : D. transit time
Description : The leakage current that flows through a photodiode with no light input ∙ A. dark voltage ∙ B. dark impedance ∙ C. dark power ∙ D. dark current
Last Answer : D. dark current
Description : A measure of conversion efficiency of a photodetector. ∙ A. Efficiency ∙ B. Responsivity ∙ C. Dark current ∙ D. Spectral response
Last Answer : B. Responsivity