Recent questions tagged electronics-engineering

Description : What are the Back ground processes in Oracle and what are they.

Last Answer : This is one of the most frequently asked question.There are basically 9 Processes but in a general system we need to mention the first five background processes.They do the house keeping activities for ... i) Lckn :: We can have upto 10 lock processes for inter instance locking in parallel sql.

Description : Which type of fiber-optic cable is the best for very high speed data? a. Single-mode step-index b. Multimode step-index c. Single-mode graded-index d. Multimode graded-index

Last Answer : a. Single-mode step-index

Description : Which type of fiber optic cable is most widely used? a. Single-mode step-index b. Multimode step-index c. Single-mode graded-index d. Multimode graded-index

Last Answer : a. Single-mode step-index

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 : The ratio of speed of light in air to the speed of light in another substance is called the a. Speed factor b. Index of reflection c. Index of refraction d. Dielectric constant

Last Answer : c. Index of refraction

Description : Refraction is the a. Bending of light waves b. Reflection of light waves c. Distortion of light waves d. Diffusion of light waves

Last Answer : a. Bending of light waves

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 : d. 300,000,000 m/s

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 : Which of the following is not part of the optical spectrum? a. Infrafed 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 is a. Lower cost b. Better security c. Wider bandwidth d. Freedom from interference

Last Answer : c. Wider bandwidth

Description : Which of the following is not a major benefit of fiber-optic cable? a. Immunity from interference b. No electrical safety problems c. Excellent data security d. Lower cost

Last Answer : b. No electrical safety problems

Description : The speed of light in plastic compared to the speed of light in air is a. Slower b. Faster c. The same d. Either lower or faster

Last Answer : a. Slower

Description : The core of a fiber optic is surrounded by a. Wire braid shield b. Kevlar 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 : Which of the cable length has the highest attenuation? a. 1 km b. 2 km c. 95 ft d. 5500 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 : b. 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 : c. Single-mode graded-index

Description : The operation of the fiber-optic cable is based on the principle of a. Refraction b. Reflection c. Dispersion d. Absorption

Last Answer : b. Reflection

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 : Which of the following is not a common application of fiber-optic cable? a. Computer networks b. Long-distance telephone systems c. Closed circuit TV d. Consumer TV

Last Answer : d. Consumer TV

Description : The laser frequency when the light has the wavelength 800 nm is a. 375 x 10^12 Hz b. 475 x 10^15 Hz c. 375 x 10^9 Hz d. 375 x 10^18 Hz

Last Answer : a. 375 x 10^12 Hz

Description : Which type of laser is the simplest to modulate directly by changing its excitation? a. Semiconductor b. Ruby c. Helium-neon d. Neodymium-YAG

Last Answer : a. Semiconductor

Description : The inner portion of the fiber cable is called a. Cladding b. Coating c. Inner conductor d. Core

Last Answer : d. Core

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 : Which of the following is used as an optical receiver in fiber optics communications a. APD b. Tunnel diode c. Laser diode d. LED

Last Answer : a. APD

Description : Which of the following is used as an optical transmitter on the Fiber Optical Communications? a. APD b. LSA diode c. PIN diode d. LED

Last Answer : d. LED

Description : What is the stage of the sand becoming a silicon? a. Liquid b. Gas c. Molten d. Hot

Last Answer : c. Molten

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 flashlamp d. Spontaneous emission

Last Answer : a. Pulses of 694 nm red light

Description : Which of the following contributes to the broadening of laser emission bandwidth? a. Doppler shift of moving atoms and molecules b. Amplification within the laser medium c. Coherence of the laser light d. Optical pumping of the laser transition

Last Answer : a. Doppler shift of moving atoms and molecules

Description : Which of the following factor does not harm laser efficiency? a. Atmospheric absorption b. Excitation energy not absorbed c. Problems in depopulating the lower laser level d. Inefficiency in populating the upper laser level

Last Answer : a. Atmospheric absorption

Description : A positive lens with a focal length of 10 cm forms a real image of an object 20 am away from the lens. How far is the real image from the lens? a. 5 cm b. 10 cm c. 15 cm d. 20 cm

Last Answer : d. 20 cm

Description : What is the photon energy for an infrared wave with frequency of 1012 Hz? a. 10.6 x 1034 joules b. 6.63 x 10-34 joules c. 6.63 x 10-22 joules d. 10.6 x 1022 joules

Last Answer : c. 6.63 x 10-22 joules

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 : 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 : Which type of laser is the simplest to modulate directly by changing its excitation? a. Semiconductor b. Ruby c. Helium-neon d. Neodymium-YAG

Last Answer : a. Semiconductor

Description : Is a non-coherent light source foe optical communications system. a. ILD b. LED c. APD d. PIN Diode

Last Answer : b. LED

Description : A dielectric waveguide for the propagation of electromagnetic energy at light frequencies a. Stripline b. Microstrip c. Laser beam d. Fiber optics

Last Answer : d. Fiber optics

Description : Laser light is ______ emission. a. Coherent b. Stimulated c. Spontaneous d. Coherent and stimulated

Last Answer : d. Coherent and stimulated

Description : What type of fiber has the highest modal dispersion? a. Step-index multimode b. Graded index multimode c. Step-index single mode d. Graded index mode

Last Answer : a. Step-index multimode

Description : Photodiodes used as fiber optic directors are a. Unbiased to generate a voltage same as a solar cell b. Forward bias c. Reversed bias d. Thermoelectrically cooled

Last Answer : c. Reversed bias

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 : b. 200,000 hours

Description : What is the insertion loss of connector-type splices for a single mode fiber optics? a. 0.51dB b. 0.31dB c. 0.49dB d. 0.38dB

Last Answer : d. 0.38dB

Description : What is the average insertion loss of fusion splice in fiber optics? a. 0.09dB b. 0.9dB c. 0.19dB d. 0.009dB

Last Answer : a. 0.09dB

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 d. Delay dispersion

Last Answer : c. Modal dispersion

Description : Longitudinal waves do not exhibit a. Polarization b. Refraction c. Reflection d. Diffraction

Last Answer : a. Polarization

Description : The wavelength of light has no role in a. Diffraction b. Interference c. Polarization d. Reflection

Last Answer : c. Polarization

Description : The real image formed by a spherical mirror is ____ relative to its object a. Erect b. Inverted c. Smaller d. Larger

Last Answer : d. Larger

Description : An object nearer to a converging lens than its focal point always has a/an ______ image. a. Inverted b. The same in size c. Virtual d. Smaller size

Last Answer : c. Virtual