Explain MCB and ELCB with connection diagram supplying single phase load.
Last Answer : OR OR Explanation: * MCB provides short circuit protection. * MCB provides overload protection * ELCB provides earth fault protection. * MCB is in series with ... occurs, the ELCB cuts off the power within the time of 0.1 sec. automatically to protect the personnel.
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586 views
1 answer
asked
May 7, 2020
by
anonymous

Write the relation between phase and line current, phase and line voltage for Star connection.
Last Answer : Line voltage is equal to root three times of phase voltage and line and phase currents are equal in star connection
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384 views
2 answers
asked
Aug 11, 2018
by
anonymous

Is it possible for a soil to consist only of one phase?
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2 views
0 answers

What is the operation of three phase induction motor
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7 views
0 answers

THREE PHASE INDUCTION MOTORS MCQ
Last Answer : 101. Insertion of resistance in the stator of an induction motor (a) increases the load torque (b) decreases the starting torque (c) increases the starting torque (d) none of the above Ans: b
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332 views
3 answers

List different starting methods of three phase synchronous motor. Explain any one of them.
Last Answer : Different Starting Methods of Three Phase Synchronous Motor: As synchronous motor is not self starting, different methods of starting are as follows: 1) By using an Induction (Pony) motor 2) ... . The rotor gets pulled into synchronism and starts running at constant speed as a synchronous motor.
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163 views
1 answer
asked
May 7, 2020
by
anonymous

Explain with neat circuit diagrams the procedures to perform no load and blocked rotor tests on three phase induction motor.
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141 views
0 answers
asked
Apr 16, 2020
by
anonymous

Explain the need and steps to conduct the reduced voltage running up test on the three phase induction motor.
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248 views
0 answers
asked
Apr 16, 2020
by
anonymous

Why is a capacitor used in a single phase motor and not in three phase motor ?
Last Answer : In 1-phase induction motor capacitor work is generate the auxiliary winding current than excite the main winding to rotor starts rotate. After rotor start rotating about 75% of their speed than auxiliary ... emf to start the motor.so,in 3-phase induction motor is self start induction motor.
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265 views
6 answers
asked
Sep 2, 2019
by
anonymous

Why is a three phase denoted by R, Y, B ?
Last Answer : phase 1 ,R =Red colour cable terminal, phase 2 Y=Yellow colour terminal cable,Phase 3 B=Blue colour cable terminal, N =Neutral. For identification.
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251 views
2 answers
asked
Aug 18, 2019
by
anonymous

State any four advantages of three phase induction motor.
Last Answer : Advantages of three phase induction motor https://youtu.be/27OIOCKN05U
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139 views
2 answers
asked
Jul 30, 2019
by
anonymous

Define balanced and unbalanced load in three phase circuit.
Last Answer : Balanced Load: When all the imedances of 3 phases are equal in magnitude and of same nature then load is said to be balanced. Unbalanced Load: When all the imedances of 3 phases are not equal in magnitude and of different nature then load is said to be unbalanced.
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260 views
1 answer
asked
Sep 6, 2018
by
anonymous

State any four applications of three phase circuits.
Last Answer : The application of three phase circuits are 1. Three phase circuit is used for power transmission over long distances. 2. Three phase circuit can produce rotating magnetic field 3. Three phase ... three phase Motors and Transformers. 4. Three phase circuit is used for power converters circuits.
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261 views
1 answer
asked
Aug 12, 2018
by
anonymous

Draw the waveform of three phase AC supply voltage.
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215 views
0 answers
asked
Aug 11, 2018
by
anonymous

State advantages of three phase over single phase.
Last Answer : Advantages of 3-phase system over 1-phase system: - 1. More output: For the same size, output of poly-phase machines is always higher than single phase machines. 2. Smaller size: For ... are self- starting: The three phase ac motors are self starting, while single phase induction motor are not.
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2.9k views
4 answers
asked
Aug 11, 2018
by
anonymous
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The slip of 400 V, three phase, 4 -pole induction motor when rotating at 1440 rpm is
Last Answer : The slip of 400 V, three phase, 4 -pole induction motor when rotating at 1440 rpm is 4 percent
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363 views
1 answer
asked
Apr 29, 2018
by
anonymous

When a V-V three phase transformer system is converted into a Δ-Δ system, increase in capacity of the system is (A) 86.6% (B) 50% (C) 57.7% (D) 73.2%
Last Answer : When a V-V three phase transformer system is converted into a Δ-Δ system, increase in capacity of the system is 73.2%
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136 views
1 answer
asked
Apr 28, 2018
by
anonymous

In a three-phase supply floating neutral is undesirable because it way give rise to?
Last Answer : In a three-phase supply floating neutral is undesirable because it way give rise to unequal line voltages across the load.
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117 views
1 answer
asked
Mar 25, 2018
by
anonymous

Three phase synchronous motor will have how many sliprings?
Last Answer : Three phase synchronous motor will have two sliprings.
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95 views
1 answer
asked
Mar 18, 2018
by
anonymous

How is a three phase cage induction motor self starting?
Last Answer : Any type of induction motor is self starting. Because the reason for torqe production require two flux displaced by some angle theta.If theta is constant with time then torqe will be constant;if ... torqe also pulsating. In induction motor this angle theta is not pulsating.so it is self starting
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160 views
1 answer
asked
Mar 17, 2018
by
anonymous

Explain power relations in three phase circuit.
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88 views
0 answers
asked
Mar 11, 2018
by
anonymous

Explain three phase half wave controller or three phase unidirectional controller.
Last Answer : Three phase half wave controller or unidirectional controller:
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240 views
1 answer
asked
Mar 8, 2018
by
anonymous

Explain Three Phase Bidirectional Delta Connected Controller.
Last Answer : Three Phase Bidirectional Delta Connected Controller:
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484 views
1 answer
asked
Mar 7, 2018
by
anonymous

What is mean by plugging in three phase induction motor?
Last Answer : Plugging in three-phase induction motor means interchanging of any two phases of a stator for quick stopping.
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156 views
1 answer
asked
Mar 3, 2018
by
anonymous
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Explain three phase bridge inverter.
Last Answer : Three phase bridge inverter: Three phase bridge inverter converts DC voltage input to three-phase variable frequency variable voltage output. DC voltage source can be a DC source or output of the rectifier. ... in proper sequence. The switch may be thyristor or IGBT etc.
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476 views
1 answer
asked
Feb 19, 2018
by
anonymous

Explain three phase full wave controller.
Last Answer : Three phase full wave controller: Three phase full wave controller is also called as the three-phase bidirectional controller. Let the load is star connected so at each phase there are antiparallel connected SCRs. ... conduct at the same time and the third phase will be open.
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269 views
1 answer
asked
Feb 14, 2018
by
anonymous

three phase to single phase cycloconverter
Last Answer : three phase to single phase cycloconverter
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516 views
1 answer
asked
Nov 16, 2017
by
anonymous

how can we reverse the direction of rotation of three phase induction motor ?
Last Answer : The direction of rotation of three phase induction motor can be reversed by plugging i.e by changing any two out of three phases of the supply to the stator of the Induction motor terminal.
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138 views
1 answer
asked
Oct 4, 2017
by
anonymous

What is difference between Star and Delta Connection?
Last Answer : Star is 1. Open ckt 2. At center point present neutral Delta is 1. Closed ckt 2. Neutral not present in this case
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152 views
1 answer
asked
Dec 22, 2017
by
anonymous

Write short notes on 3 phase AC system.
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120 views
0 answers
asked
Aug 11, 2018
by
anonymous

What is the voltage in 3 phase line?
Last Answer : between 430 to 440 v
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283 views
4 answers
asked
Dec 22, 2017
by
anonymous

How a three phase three line system can be converted to three phase four line system using Scott connection?
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4 views
0 answers

Explain with the neat circuit diagram only the scott connection scheme for conversion of three phase supply to two phase supply. Name one application of the same.
Last Answer : Three-phase to Two-phase Transformation (Scott Connection of Transformers): Working: i) Scott connection can be used for three-phase to two-phase conversion using two single-phase transformers ... a 3-phase system with a two-phase system with the flow of power in either direction.
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441 views
1 answer
asked
May 22, 2020
by
anonymous

Which of the following 3-phase connection of a transformer causes interference with the neighbouring communication lines: (A) Delta-Star (B) Star-Delta (C) Delta-Delta (D) Star-Star
Last Answer : Which of the following 3-phase connection of a transformer causes interference with the neighbouring communication lines: Star-Star
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357 views
1 answer
asked
May 8, 2018
by
anonymous

UPS- How to give Connection?
Last Answer : Ans. Means Uninterrupted power supply. To give UPS connection, first normal supply is kept off. Then, loads of essential and non essential are to be segregated. Essential loads are to be brought under single point of control. Then, UPS can be connected.
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9 views
1 answer

State functions of ; i) Cable box ii) Guard wire iii) Shackle insulator iv) Stay wire used in service connection
Last Answer : i) Function of Cable box: To hold and inspect incoming and outgoing terminals ii) Function of Guard wire : A grounded conductor placed beneath an overhead transmission line in order to ground ... in service connection: To give mechanical Support to pole, line and prevent leakage current if any
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147 views
1 answer
asked
Sep 20, 2018
by
anonymous

Why underground service connections are service connections are costly than overhead service connection
Last Answer : Reason: Underground service connection is given by underground cable. This cable is costly than bare conductor. Sometimes cable trench is required for cable laying, which requires additional cost. So underground service connections are costly than overhead service connection.
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125 views
1 answer
asked
Sep 18, 2018
by
anonymous

Define service connection and state types connection and state types of overhead service connection
Last Answer : Service Connection:- It is the input conductor or wire which is carried out from supply company (authorities) pole to consumers' main board or premises. Types of overhead service ... 1. Overhead service connection with Bare conductor 2. Overhead service connection with weather proof cable
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263 views
1 answer
asked
Sep 18, 2018
by
anonymous

State the principle of solar cell. What is necessity of series and parallel connection of solar cells.
Last Answer : Principle of solar cell:- Working:- Solar cell operates on principle of Photo-voltaic effect Solar cell works in following steps: The solar cell is composed of a P-type ... of Voltage & Current rating it is necessity of connecting series and parallel connection of solar cells.
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116 views
1 answer
asked
Sep 7, 2018
by
anonymous

State necessity of series connection and parallel connection of batteries.
Last Answer : Necessity of series connection of batteries: 1. The batteries are available with some specific terminal voltages. e. g. 6V, 12V, 24V, 48V etc. 2. If we want to have some terminal voltage other than ... batteries of capacities I1, I2, I3, I4 . are connected in parallel, all having identical emfs.
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87 views
1 answer
asked
Sep 4, 2018
by
anonymous

number of windings of a coil in a stator of ac motor for ey slot ac motor
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134 views
0 answers

Compare star and Delta Connection.
Last Answer : Compare Star and Delta connected system: Star connected system Delta connected system In STAR connection, the starting or finishing ends (Similar ends) of three coils are connected together to form the ... VPH Line Current is √3 times of Phase Current. i.e. IL = √3 IPH
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3.1k views
4 answers
asked
Aug 12, 2018
by
anonymous
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Which of the following connection of transformers will give highest value of secondary voltage ? (A) Delta primary delta secondary (B) Delta primary star secondary (C) Star primary star secondary (D) Star primary delta secondary
Last Answer : Which of the following connection of transformers will give highest value of secondary voltage ? (A) Delta primary delta secondary (B) Delta primary star secondary (C) Star primary star secondary (D) Star primary delta secondary
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584 views
1 answer
asked
May 8, 2018
by
anonymous

Last Answer : Direction of rotation of a split phase motor can be reversed by reversing the connection of either running winding or starting winding.
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358 views
1 answer
asked
Mar 20, 2018
by
anonymous

How different are people really?
Last Answer : On a universal level we are all one, as we are one with every organism, all created “equal” in natures grand design. On a “personal” level we are vastly different in how our nature/nurture/cultural dichotomies show up. Sooo…the usual double edged sword.
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3 views
1 answer
asked
Feb 27
by
anonymous

Do you find yourself feeling a special bond with certain others on Fluther?
Last Answer : Definitely although I hate to be cliquey. There are some who you just have an affinity for and an ease with. and those with superior intelligence who agree with me
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1 view
1 answer
asked
Feb 27
by
anonymous
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How do I open gaming ports on my Belkin router?
Last Answer : is there a thing called DMZ on the website. under a tab named application & gaming?
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2 views
1 answer
asked
Feb 26
by
anonymous

List three important characteristics of an electric circuit.
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256 views
0 answers
asked
Jun 29, 2019
by
anonymous

Consider a circuit with three parallel branches connected across a DC supply. What is the ratio of the branch currents I1 : I2 : I3 if the branch resistances are in the ratio of 2 : 3 : 4 respectively? A) 2 : 3 : 4 B) 6 : 4 : 3 C) 4 : 3 : 2 D) None of these
Last Answer : Consider a circuit with three parallel branches connected across a DC supply. What is the ratio of the branch currents I1 : I2 : I3 if the branch resistances are in the ratio of 2 : 3 : 4 respectively? A) 2 : 3 : 4 B) 6 : 4 : 3 C) 4 : 3 : 2 D) None of these
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213 views
1 answer
asked
Apr 29, 2018
by
anonymous
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When three resistors with unequal values are connected in parallel, _______ A) The current across the resistors is the same B) The voltage drop across the resistors is the same C) The voltage drops across the resistors is proportional to the resistance of each resistor D) None of these
Last Answer : When three resistors with unequal values are connected in parallel, The voltage drop across the resistors is the same
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121 views
1 answer
asked
Apr 29, 2018
by
anonymous
