Description : Explain triggering of SCR using opto-coupler. State its advantages.
Last Answer : Triggering of SCR using opto-coupler: A simple opto-coupler based triggering circuit for SCR is shown in the figure. An optocoupler or opto-isolator is a combination of light source ... is small size and light weight device. iii)Interfacing with logic circuits is easily possible.
Description : Write working of opto coupler as an isolator.
Last Answer : Optocoupler is as shown in fig. it consist of LED as an light source and phototransistor act as light detector. When input pulse is applied LED turns ON.Light emitted by LED focused on CB ... starts flowing.As input pulse reduces to zero LED turns OFF collector current becomes zero.
Description : Mention the advantages of opto-couplers:
Last Answer : *Better isolation between the two stages. *Impedance problem between the stages is eliminated. *Wide frequency response. *Easily interfaced with digital circuit. *Compact and light weight. *Problems such as noise, transients, contact bounce,.. are eliminated.
Description : Which one is an antenna coupling unit? A. Coupler B. Diplexer C. Lecher wire D. Duplexer
Last Answer : B. Diplexer
Description : Not a reason for the use of an antenna coupler. A. To make the antenna look resistive B. To provide the output amplifier with the correct load impedance C. To discriminate against harmonics D. To prevent re-radiation of the local oscillator
Last Answer : D. To prevent re-radiation of the local oscillator
Description : A component that samples the microwave signal travelling in one direction down to the transmission line A. Isolator B. Combiner C. Directional coupler D. Attenuator
Last Answer : C. Directional coupler
Description : Best choice of transmission line component to couple a coaxial line to a parallel-wire line A. Shorting B. Balun C. Slotted line D. Directional coupler
Last Answer : B. Balun
Description : Referred to as a ferrite device that can be used in lieu of a duplexer to isolate a microwave transmitter and receiver when both are connected to the same antenna. A. Isolator B. Circulator C. Coupler D. Diode.
Last Answer : B. Circulator
Description : A device that connects two dissimilar networks and performs the protocol conversion. A. Gateway B. Coupler C. Transformer D. Converter
Last Answer : A. Gateway
Description : To couple a coaxial line to parallel line, it is better to use a ______. A. Slotted line B. Quarter-wave transformer C. Directional Coupler D. Balun
Last Answer : D. Balun
Description : To connect coaxial line to a parallel-wire _________ is the best to use. A. directional coupler B. quarter-wave transformer C. balun D. slotted line
Last Answer : C. balun
Description : What is the purpose of having input and output capacitors in three terminal IC regulators?
Last Answer : A capacitor connected between the input terminal and ground cancels the inductive effects due to long distribution leads. The output capacitor improves the transient response.
Description : Give some examples of monolithic IC voltage regulators
Last Answer : 78XX series fixed output, positive voltage regulators 79XX series fixed output, negative voltage regulators 723 general purpose regulator.
Description : What are the advantages of IC voltage regulators?
Last Answer : *low cost *high reliability *reduction in size *excellent performance
Description : What is a compander IC? Give some examples.
Last Answer : The term companding means compressing and expanding.In a communication system, the audio signal is compressed in the transmitter and expanded in the receiver. Examples : LM 2704- LM 2707 ; NE 570/571.
Description : Why IC 741 is not used for high frequency applications?
Last Answer : IC741 has a low slew rate because of the predominance of capacitance present in the circuit at higher frequencies. As frequency increases the output gets distorted due to limited slew rate.
Description : What is the use of buried n+ layer in monolithic IC transistor?
Last Answer : The buried n+ layer provides a low resistance path in the active collector region for the flow of current
Description : Define opto-isolator. Explain the role of opto-isolator in PLC.
Last Answer : Role of optoisolator in PLC: An optoisolator is a semiconductor device that uses a short optical transmission path to transfer an electrical signal between circuits or elements of a ... disruptions, optoisolators offer a safe interface between high-voltage components and low-voltage devices.
Description : What is a coupler signal ?
Last Answer : coupler signal K.
Description : When a coupler nut is subjected to crushing stress, crushing failure can be avoided if _____ a. crushing stress induced is more than permissible crushing stress in the nut b. permissible crushing ... threads c. crushing stress induced is equal to permissible crushing stress d. all of the above
Last Answer : b. permissible crushing stress is more than crushing stress induced in the threads
Description : Curl cannot be employed in which one of the following? a) Directional coupler b) Magic Tee c) Isolator and Terminator d) Waveguides
Last Answer : d) Waveguides
Description : Bus coupler is very essential in arrangement (a) single bus (b) double bus, double breaker (c) main and transfer bus (d) all of the above
Last Answer : (c) main and transfer bus
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 : in a directional coupler that is designed to sample the incident energy, what happens to the two portions of the wavefront when they arrive at the pickup probe?
Last Answer : The wavefront portions add.
Description : What is the purpose of the absorbent material in a directional coupler?
Last Answer : Absorb the energy not directed at the pick-up probe and a portion of the overall energy
Description : How far apart are the two holes in a simple directional coupler?
Last Answer : 1/4 wavelength.
Description : What is the primary purpose of a directional coupler?
Last Answer : Sampling energy within a waveguide.
Description : Describe a directional coupler.
Last Answer : A fiber optic coupler that prevents the transfer of power between input fibers.
Description : Which type of optical splitter (Y-coupler or T-coupler) splits only a small amount of power from the input fiber to one of the output fibers?
Last Answer : T-coupler
Description : Which fiber optic component (splice, connector, or coupler) makes a permanent connection in a distributed system?
Last Answer : Splice.
Description : Why is the coupler pressurized with nitrogen?
Last Answer : To aid in heat transfer and prevent corona and arcing
Description : What is the purpose of an antenna coupler
Last Answer : It matches the impedance of an antenna to that of a transmission line at any desired frequency.
Description : What are the tuning modes for the coupler group discussed?
Last Answer : Automatic, semiautomatic, and manual.
Description : To measure incident power, you must rotate the coupler detector of the wattmeter so that the arrow indicating power flow points toward which end of the transmission line?
Last Answer : Load.
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 : A coupler which consists of a series of lenses and a partly reflective surface ∙ a. Beam-splitting coupler ∙ b. Reflective star coupler ∙ c. Fused coupler ∙ d. None of these
Last Answer : ∙ a. Beam-splitting coupler
Description : In SONET, OC-1 stands for: a. Optical Carrier level one b. Optical Coupler unidirectional c. Optical Channel one d. Optical Cable type 1
Last Answer : a. Optical Carrier level one
Description : One ofthe followingis not a reason forthe use of anantenna coupler: a. To make the antenna look resistive b. To provide the output amplifier with the correct load impedance c. To discriminate against harmonics d. To prevent reradiation of the local oscillator
Last Answer : d. To prevent reradiation of the local oscillator
Description : To couple a coaxialline toa parallel-wire line,itisbesttouse a a. slotted line b.balun c. directional coupler d. quarter-wave transformer
Last Answer : b.balun
Description : Fortransmission-line loadmatchingover a range offrequencies,itisbesttouse a a. balun b. broadband directional coupler c. double stub d. single stub of adjustable position
Last Answer : c. double stub
Description : What maximum load would you place on a right angle coupler?
Last Answer : 630kg (or 630kgf or 6.25kN)
Description : What is the height of the base lift (kicker lift) on a typical tube and coupler scaffold? a. 225mm (9 inches) b. 300mm (12 inches) c. 150mm (6 inches) d. 100mm (4 inches)
Last Answer : c. 150mm (6 inches
Description : P-N junction is (A) a rectifier. (B) an amplifier. (C) an Oscillator. (D) a Coupler.
Last Answer : (A) a rectifier.
Description : Describe the working of directional coupler with neat diagram.
Last Answer : Directional couplers are devices that will pass signal across one path while passing a much smaller signal along another path. One of the most common uses of the directional coupler is to ... . The frequency determines the separation of the two holes as a fraction of the wavelength.
Description : Draw a neat sketch of ‘Locomotive coupler’ mechanism. Explain its working in brief.
Last Answer : Figure: Coupler Rod of Locomotive (Link AD = Link BC = Crank Link CD = Coupling Rod Link AB = Fixed Link = Frame) Working of Coupler Rod of Locomotive: It is an ... center distance between them. This mechanism is meant for transmitting rotary motion from one wheel to the other wheel.
Description : Why is a shaft coupler used between turbine and generator ?
Last Answer : For easy transmission torque or rotation angle and can also use for the protection of the safety devices shaft cannot be separated from the shaft during motion coupling will be damaged first so as avoid to the damaged of motor or other transmission parts.
Description : In a directional coupler: (1) Isolation (dB) equals coupling plus directivity (2) Coupling (dB) equals isolation plus directivity (3) Directivity (dB) equals isolation plus coupling (4) Isolation (dB) equals (coupling) (directivity)
Last Answer : In a directional coupler: Isolation (dB) equals coupling plus directivity.
Description : Who do you spell "in-fat-ic" and what's it mean?
Last Answer : Was it “emphatic”? Which basically just means forceful/vigorous – in other words “giving it your all”.
Description : What is the full form of 'IC' ? -How To ?
Last Answer : The full form of 'IC' is Integrated Circuit
Description : What material is the IC chips of a computer made of? -General Knowledge
Last Answer : Silicon Integrated circuit (IC), also called microelectronic circuit, microchip, or chip, an assembly of electronic components, fabricated as a single unit, in which miniaturized active devices ( ... only a few square millimetres. The individual circuit components are generally microscopic in size.