Recent questions tagged phase

asked May 21, 2020 by anonymous

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asked May 21, 2020 by anonymous

State classification of Phase controlled rectifiers.

Last answer: Classification of phase controlled rectifiers:

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asked May 16, 2020 by anonymous

Single phase transformer

Last answer: Single phase Transformer Transformer

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asked May 7, 2020 by anonymous

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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212 views 1 answer

asked May 7, 2020 by anonymous

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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66 views 1 answer

asked May 7, 2020 by anonymous

State suitable single phase motor for following applications: (i) Table fan (ii) Mixers and Grinders

Last answer: Application Suitable Single Phase Motor Table Fan 1) Capacitor split phase motor 2) Capacitor start capacitor run motor Mixers and Grinders 1) Universal motor 2) A.C. Series motor

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53 views 1 answer

asked May 2, 2020 by anonymous

Draw & explain operation of phase detector.

Last answer: In phase detector, the op-Amp basically acts as a zero crossing detector. If a sine wave is applied at the i/p, we get square wave at the op-Amp o/p (at point ... to two channel of the CRO. The time duration between the pulses corresponding to voltages represent the phase between them.

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71 views 1 answer

asked Apr 27, 2020 by anonymous

Explain the concept of lagging and leading phase angle by waveform.

Last answer: i) Leading phase angle : When two ac quantities of same frequency do not attain their respective zero or peak values simultaneously, then the quantities are said to be out-of-phase quantities. The ... Similarly, in the second diagram, the voltage is said to be lagging the current by Φ.

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64 views 1 answer

asked Apr 27, 2020 by anonymous

Explain the procedure to perform Short Circuit test on single phase transformer with circuit diagram.

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asked Apr 16, 2020 by anonymous

Explain with neat circuit diagrams the procedures to perform no load and blocked rotor tests on three phase induction motor

Explain with neat circuit diagrams the procedures to perform no load and blocked rotor tests on three phase induction motor.

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86 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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59 views 0 answers

asked Sep 2, 2019 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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129 views 6 answers

asked Aug 21, 2019 by anonymous

Define Amplitude and Phase of Sinusoidal quantity.

Last answer: Amplitudes are expressed either as instantaneous values or mostly as peak values. Amplitude is the fluctuation or displacement of a wave from its mean value. Phase is the position of a ... . Phase an expression of relative displacement between or among waves having the same frequency .

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asked Aug 21, 2019 by anonymous

working principle of single phase motor

Last answer: The Stator of single phase induction motor houses two windings 1. Main (Running) winding 2. Auxiliary (Starting ) winding Rotor of single phase induction motor is ... with starting winding or a capacitor may be permanently connected in series with Auxiliary (Starting ) winding.

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94 views 1 answer

asked Aug 18, 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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172 views 2 answers

asked Aug 13, 2019 by Alacrity

the volt per turn of a certain single phase transformers is 1.7. the transformer has a step ratio of 3825/255volt. calculate the respective number of turns in each winding

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asked Aug 12, 2019 by anonymous

What is phase failure relay and how it's work?

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asked Jul 30, 2019 by anonymous

Explain the working of a single phase capacitor start induction motor.

Last answer: Single phase capacitor start induction motor https://youtu.be/31lvvzU5Puc

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153 views 2 answers

asked Jul 30, 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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101 views 2 answers

asked Jul 26, 2019 by anonymous

Explain construction and working principle of single phase transformer.

Last answer: A single phase transformers is an electrical device that accepts single-phase AC power and outputs single-phase AC. PRINCIPLE... The single-phase transformer works on the principle of ... and secondary windings. Thin steel laminations shall be employed to prevent power losses from the core.

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346 views 4 answers

asked Jul 25, 2019 by anonymous

Give the operation of single phase full wave bridge controlled converter with RL load with a neat diagram. Also draw its waveform.

Last answer: Single phase fully control bridge converter with RL load: 1. During positive half cycle of input voltage, T1 and T2 are forward biased and during negative half cycle, T3 and T4 are forward biased. Therefore, T1-T2 ... cycle till the firing of next pair of SCRs as shown in the waveform.

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164 views 1 answer

asked Sep 22, 2018 by anonymous

Explain following techniques related to energy conservation in transmission and distribution system. (i) By balancing phase currents (ii) Variable technical losses (I2R losses).

Last answer: (i) Balancing Phase currents: Proper (healthy balanced) three phase loads always draw equal currents in all lines but single phase loads in the 3 phase 4 wire system or loads connected between two ... . 11) Minimize I2R losses. 12) Balance the load currents. 13) Regulate the system voltages.

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110 views 1 answer

asked Sep 20, 2018 by anonymous

Split phase induction motor

Last answer: Split phase induction motor : There are two windings used in split phase induction motor. It is a type of single-phase induction motor. There are two winding one is called main winding and ... motor have low starting torque it is used for small fans, blowers, centrifugal pumps, grinders etc.

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179 views 1 answer

asked Sep 7, 2018 by anonymous

What is Phase sequence? Draw waveforms of 3 phase emf.

Last answer: Phase sequence: It is the order in which the three phases reach their peak or maximum values. It is shown in below fig. the phase sequence is A-B-C (or R-Y-B). In the following waveforms, it is ... 120º, B- phase voltage attains its positive maximum value. So the phase sequence is R-Y-B.

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asked Sep 7, 2018 by anonymous

Define balanced 3 phase load.

Last answer: Balanced 3 phase Load: Balanced three phase load is defined as star or delta connection of three equal impedances having equal real parts and equal imaginary parts. It takes same current of equal magnitude and equal phase angle.

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57 views 1 answer