Description : Which of the following bus-bar schemes has the lowest cost ? (a) Ring bus-bar scheme (b) Single bus-bar scheme (c) Breaker and a half scheme (d) Main and transfer scheme
Last Answer : (b) Single bus-bar scheme
Description : What are different types of busbar arrangement Schemes in Substations?
Last Answer : Different switching schemes or busbar arrangement scheme employed in switch-yard are: Single Bus Scheme Double bus single breaker scheme Main and Transfer busbar scheme Double bus single breaker scheme Breaker and half scheme Ring main bus scheme
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 : Which distribution system is more reliable? (a) Ring main system (b) Tree system (c) Radial system (d) All are equally reliable
Last Answer : Ans: A
Description : Factors on which material of station busbar depends?
Last Answer : Some of the factors on which station busbar depends are: Current Carrying capacity Short Circuit Stresses Establishing minimum electrical clearances
Description : Why busbar protection is needed?
Last Answer : (a) Fault level at busbar is high (b) The stability of the system is affected by the faults in the bus zone. (c) A fault in the bus bar causes interruption of supply to a large portion of the system network.
Description : What are the protections are there for BUSBAR?
Last Answer : Instantaneous over current protection Bus bar differential protection Local breaker back up protection
Description : For more complete vessel protection when using an impressed current cathodic system _____________. A. all ship's service alternators have additional temperature sensing devices and a thermal recorder ... with the hull and the propeller shaft is grounded through a slip ring/brush arrangement
Last Answer : Answer: D
Description : As a result of a mechanical malfunction in one of the ship's service generators operating in parallel, you must secure that generator. In order to prevent a possible overload to the ... feeder circuit breakers, the malfunctioning prime mover turbine throttle trip, and the generator circuit breaker.
Last Answer : Answer: B
Description : For distribution network which type of Switching scheme is employed?
Last Answer : For distribution network Ring Main busbar scheme is employed. It has the provision that if power interruption occurs to one bus section due to maintenance or fault, power can be fed the bus from other side of the power system.
Description : Extremely large or small volumes of fluids are generally best routed through the shell side of a shell and tube heat exchanger, because of the (A) Less corrosion problems (B) Flexibility possible in the baffle arrangement (C) Low pressure drop (D) High heat transfer co-efficient
Last Answer : (B) Flexibility possible in the baffle arrangement
Description : The purpose of the automatic bus transfer shown in the illustration is to ___________. EL-0014 A. stepdown voltage to the lighting distribution panel B. provide emergency power to ... emergency switchboard from the main switchboard D. provide overcurrent protection to the lighting distribution panel
Description : . A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because (A) Total heat transfer area of ... in a single effect is much lower than that in any effect in a multi-effect system
Last Answer : (B) Total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect
Description : Which of the following medium is employed for extinction of arc in air circuit breaker ? (a) Water (b) Oil (c) Air (d) SF6
Last Answer : (c) Air
Description : Which of the following medium is employed for extinction of arc in air circuit breaker ?(a) Water (b) Oil(c) Air (d) SF6
Last Answer : Which of the following medium is employed for extinction of arc in air circuit breaker ?(a) Water (b) Oil(c) Air (d) SF6
Description : Which one of the following is the advantage of connecting two dry cells in parallel instead of in series? Is it because the parallel arrangement: w) gives twice the EMF of one dry cell x) has no ... circuit half as fast as would a single cell z) has half the internal resistance of a single cell
Last Answer : ANSWER: Z -- HAS HALF THE INTERNAL RESISTANCE OF A SINGLE CELL
Description : As shown in the illustration, 'B' is a ____________. EL-0058 A. single-pole, double-throw switch B. double-pole, single-throw switch C. double-pole, double-throw switch D. circuit breaker
Last Answer : Answer: C
Description : In the illustration, the contacts between terminals 26 and 27 should be closed when _________. EL-0046 A. using one generator in isochronous mode only B. using two or more generators in ... through varying loads in parallel or single operation D. the circuit breaker is closed for that generator
Description : Which of the following distribution systems is more reliable ? (a) Radial system (b) Tree system (c) Ring main system (d) All are equally reliable
Last Answer : (c) Ring main system
Description : Why is the busbar sectionalized ?
Last Answer : Answer : If an error occurs in any part of the busbar, the operation of the entire busbar system will not stop. The maximum success of this system is due to the interconnection of different sections of the circuit and the smooth distribution in the outgoing circuit.
Description : Explain differential protection of busbar.
Last Answer : Differential protection Scheme for bus bar: Under normal conditions the sum of the currents entering the bus bar zone is equal to those leaving it and no current flows through the relay ... . The difference of these currents will flow through the relay coil causing opening of circuit breaker.
Description : State factors deciding size of busbar chamber for commercial installation.
Last Answer : Size of busbar chamber depends on following factors. Total load or load current on installation Future load on installation No. of tappings provided on buabar Spare feeders provided if any ... . Incoming and outgoing wires or cables are connected to bus-bar by screw and nut arrangement.
Description : State function of Busbar and which material is used for busbar?
Last Answer : Function of Busbar Bus-bar: - Distribute the load on 3-phase four wire systems. To provide number of connection of incoming line and to provide easy way to connect number of sub circuit. ... to the element. This element means busbar Material is used for busbar: 1. Copper 2. Alluminium
Description : To remove an alternator operating in parallel with another unit from the main electrical bus, you must FIRST _________. A. adjust the power factor on both units B. set the desired voltage on ... C. open the circuit breaker on the outgoing alternator D. remove the load from the outgoing alternator
Description : During maintenance of circuit breakers, _______________. A. always smooth roughened contact surfaces with a file B. never pass more than rated breaker current through the overload heater element C. ... wear and misalignment of main contacts D. assume heater elements installed are of correct size
Description : Undervoltage trips are frequently installed on switchboard circuit breakers to trip ____________. A. out generators in the event of severe arcing or sparking B. out generators when there is reversal of power ... , but continues to run D. out generators when there is low voltage in the main circuit
Description : A reverse-current relay will prevent AC generator motorization by ____________. A. automatically redirecting the load B. automatically speeding up the prime mover C. tripping the panel board main switch D. tripping the generator circuit breaker
Description : The devices labeled 'L' in the illustration are _________. EL-0003 A. load lights indicating that the generator breaker is closed and the generator is supplying power to the main bus B. ... o'clock position the lights are at their dimmest or out indicating the the generators are in phase
Description : A ground in an electrical circuit outside the engine room _____________. A. cannot be detected under normal conditions B. is of no consequence to engineering personnel C. is indicated at the branch circuit breaker panel D. is indicated by the ground detecting lamps on the main switchboard
Description : The purpose of a main switchboard circuit breaker's reverse-power trip is to _____________. A. prevent main circuit overload B. protect the circuit breaker blowout coil C. prevent alternator motorization D. prevent low voltage tripout
Description : What is the main problem of the circuit breaker?
Last Answer : When the contacts of the breaker are separated, an arc is struck between them. This arc delays the current interruption process and also generates enormous heat which may cause damage to the system or to the breaker itself. This is the main problem.
Description : What are the main parts of 220 kV Circuit Breaker?
Last Answer : Pole column filled with SF6 Pneumatic drive system with compressed air circuit Control cubicle unit
Description : What is the main drawback of a single phase half bridge inverter?
Last Answer : It require a 3-wire dc supply.
Description : Water supply system includes (A) Digging a well for water (B) Construction of dams (C) Construction of canals (D) Entire arrangement from source to distribution
Last Answer : (D) Entire arrangement from source to distribution
Description : Which of the following statements about the federal system in India are true? I. The Constitution of India provides for a three-fold distribution of legislative powers between the Union and the State Government. II. Both the Union and ... III (2) II, III and IV (3) I, III and IV (4) I, II and IV
Last Answer : (3) I, III and IV
Description : In the system shown in the illustration, the station at section I is unable to signal any other station nor is any other station able to signal the station in section I. The station can, however, ring ... only a single station to respond to itself. D. The switch at component 'C' is stuck open.
Description : State weather the following statement is true or false for Token Bus 1).It is a linear or tree- shaped cable onto which the stations are attached. 2). the token propagates around the logical ring, with only the token holder ... 3. false C. 1. false, 2. false, 3. false D. 1. true, 2. true, 3. false
Last Answer : D. 1. true, 2. true, 3. false
Description : If the illustrated motor fails to start and gives a loud hum when the start button is pushed, the problem is ________. EL-0007 A. one of the phases to the motor is not energized because of ... electrical distribution system D. 'OL1' is open because of 'T1' overload causing the motor to single phase
Last Answer : Answer: A
Description : Tilth is related to a. Soil aggregates shape b. Soil aggregates size distribution c. Soil aggregates arrangement d. All of these
Last Answer : d. All of these
Description : Which of the following is/are true concerning electric power operated watertight door systems? A. Each motor driven door must use the main bus as its source of power. B. Each distribution panel for ... to permit quick activation of the system. D. Each system must have a separate branch circuit.
Description : A ground is indicated by the ground-detecting system on the main electrical switchboard. The FIRST step in locating the actual ground is to _____________. A. close all circuit breakers in ... ground detection system indicates normal C. change over generators D. check each circuit with a megohmmeter
Description : The part of the shipboard electrical system used to control the distribution of power to the branch circuits, is the _____________. A. bridge control panel B. disconnect links C. governor relay box D. main switchboard
Description : What are the main items used in over head distribution system?
Last Answer : a. Conductor material. b. Pole. c. Cross arm. d. Insulators. e. Strain insulator. f. Post insulator. g. Stay wire. h. Support with insulator and stay lightner.
Description : In accordance with Coast Guard Regulations (46 CFR), a circuit breaker located in the machinery space and installed in a 440V AC system must _____________. A. be dependent upon mechanical ... the maximum asymmetrical shortcircuit current available at the point of application D. all of the above
Description : Why we use Vacuum Circuit Breaker in High Transmission System and not Air Circuit Breaker?
Last Answer : A:Vacuum has high arc quenching property compare to air . The dielectric strength of vacuum is equal to 8 times than air . Hence vacuum circuit breaker is used in High voltage line and air circuit breaker is used in low voltage lines.
Description : What do mean by trip free system in breaker?
Last Answer : In trip free the breaker is free to trip at any time. If both close and trip signal is present at same time (instant) the breaker will attempt to close and positively trip. When the breaker trips it will not close again even if closing signal exists because of anti pumping feature.
Description : Generally the gap between the contact breaker points is kept between a) 0 .1 to 0.3 mm b) 0.2 and 0.4 mm c) 0.3 and 0.5 mm d) 0 .4 and 0.6 mm
Last Answer : c) 0.3 and 0.5 mm
Description : Which of the device is employed in substation to limit the short circuit current in the power system: a) Shunt condenser b) Reactor c) Series capacitor d) Shunt capacitor
Last Answer : Ans: B
Description : Auger boring (A) Is the most primitive method for making a hole in the ground (B) Is generally employed in cohesive and other self soils above water table (C) Is most economical upto a depth of 5 metres (D) All the above
Last Answer : Answer: Option D
Description : Generally in all researches, an abstract of each article has been prepared which focuses upon Options: A) The central theme of the research paper B) The research-innovation employed in research paper C) The effective conclusions of the research paper D) All of the above
Last Answer : D) All of the above