What is the supply rated o/p if two single phase transformer connect to give three phase o/p from a three phase I/p?

What is the supply rated o/p if two single phase transformer connect to give three phase o/p from a three phase I/p?
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1 Answer

Answer :

A. Each transformer is only capable of supplying 86.6%of its o/p rating
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Related questions

How to connect two single phase transformer to give three phase o/p from a three phase I/p ?

Description : How to connect two single phase transformer to give three phase o/p from a three phase I/p ?

Last Answer : A. They would have to connect in an open-delta.

Can a Single Phase Transformer be used on a Three Phase source?

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What are the advantages of three phase transformer over three single phase transformer?

Description : What are the advantages of three phase transformer over three single phase transformer?

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Description : What are the advantages of three single phase transformer over three phase transformer?

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What is single and three phase transformer?

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Why the open circuit test on a transformer is conducted at rated voltage?

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Last Answer : A:The open circuit on a transformer is conducted at a rated voltage because core loss depends upon the voltage. This open circuit test gives only core loss or iron loss of the transformer.

What are the various types of three phase transformer connections?

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What happen when Transformer is given DC supply ?

Description : What happen when Transformer is given DC supply ?

Last Answer : When DC supply is given to the transformer primary winding no back emf is induced in the transformer. Importance of Back emf is that it limits the current drawn by the machine. In the absence ... in burning down of primary winding. So when dc supply is given to transformer primary windings will burn

What will happen if DC supply is given on the primary of a transformer?

Description : What will happen if DC supply is given on the primary of a transformer?

Last Answer : A. Mainly transformer has high inductance and low resistance. In case of DC supply there is no inductance, only resistance will act in the electrical circuit. So, high electrical current will flow through primary side of the transformer. Due to this the coil and insulation will burn out.

What will happen if transformer in parallel connection have different phase sequence ?

Description : What will happen if transformer in parallel connection have different phase sequence ?

Last Answer : If the phase sequence is in an incorrect manner, in every cycle each pair of phases will get short-circuited.

Can Single Phase Transformers be used for Three Phase applications?

Description : Can Single Phase Transformers be used for Three Phase applications?

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Can Transformers develop Three Phase power from a Single Phase source?

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Last Answer : A. NO. Phase converters or phase shifting devices such as reactors and capacitors are required to convert single phase power to three phase.

When a given transformer is run at its rated voltage but reduced frequency, its?

Last Answer : When a given transformer is run at its rated voltage but reduced frequency, its core flux density is increased.

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Description : If a transformer is switched on to a voltage more than the rated voltage?

Last Answer : If a transformer is switched on to a voltage more than the rated voltage its power factor will deteriorate.

A 4000 kVA, 11 kV/132 kV delta-star connected 3-phase transformer has reactance, x1 = 0.12 p.u.

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Explain construction and working principle of single phase transformer.

Description : 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.

A single phase transformer has resistance and reactance of 0.2 pu and 0.6 pu respectively. Its pu voltage

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A 230 V/460 V single-phase transformer operating at 20 A and unity power factor has primary referred

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Last Answer : A 230 V/460 V single-phase transformer operating at 20 A and unity power factor has primary referred resistance of 0.2 Ω and reactance of 0.5 Ω. The approximate primary induced emf is 226 V

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Description : In a single-phase transformer, the magnetizing current is (A) in phase with the no-load current (B) in quadrature with the no-load current (C) the product of no-load current and power factor (D) in phase with the flux in the core

Last Answer : In a single-phase transformer, the magnetizing current is in phase with the flux in the core

Can the transformers be used at higher frequencies than rated frequency?

Description : Can the transformers be used at higher frequencies than rated frequency?

Last Answer : A. Yes. Transformers can be used at higher frequencies than rated frequency. However as the frequency increases voltage regulation decreases.

why transformers are rated in kVA ?

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Last Answer : A:Copper loss of a transformer depends on current and iron loss on voltage . Hence total losses depends on Volt- Ampere and not on the power factor. That is why the rating of transformers are in kVA and not in kW.

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Description : The kVA rating of Three-phase transformer with Voltage = 200V and Current = 100A will be :  (A) 34.64 kVA (B) 75 kVA (C) 20 kVA (D) None of the above

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52 A transformer has 1000 primary turns, connected to 250V ac supply. To get 400V secondary voltage the no of secondary turns should be A. 1600 B. 250 C. 400 D. 1250

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Last Answer : A. 1600

An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to

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What will happen if the primary of a transformer is connected to D.C. supply?

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The inrush current of a transformer at no load is maximum if the supply voltage is switched on

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Last Answer : At 0.866 time voltage value

A transformer cannot raise or lower the voltage of a D.C. supply because?

Last Answer : A transformer cannot raise or lower the voltage of a D.C. supply because Faraday's laws of electromagnetic induction are not valid since the rate of change of flux is zero.

If the supply frequency to the transformer is increased, the iron loss will?

Last Answer : If the supply frequency to the transformer is increased, the iron loss will increase.

In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of?

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Why does a transformer only work with an AC supply?

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Last Answer : The transformer work depends on the induction as main principle ,for that AC is the right means

why transformer don't work on DC supply?

Description : why transformer don't work on DC supply?

Last Answer : A  DC  current  does  not  produce  a  changing  magnetic   field   which  is   capable  of  inducing   current   on   the   secondary    windings   of   a   transformer   through  mutual   induction   process.

Is it Possible to Change Three Phase to Two Phase or Vice-Versa with Standard Transformers?

Description : Is it Possible to Change Three Phase to Two Phase or Vice-Versa with Standard Transformers?

Last Answer : Yes. This is a very practical application for standard single phase off-the-shelf transformers. Some typical voltage combinations are as follows: 480 volts three phase to 240 volts two phase, or 240 volts ... 240 volts three phase to 240 volts two phase. Please refer to us for an exact schematic.

6 In a two winding transformer, the primary and secondary induced emf E1 & E2 are always A. equal in magnitude B. anti phase with each other C. in phase with each other D. determined by load on transformer secondary

Description : 6 In a two winding transformer, the primary and secondary induced emf E1 & E2 are always A. equal in magnitude B. anti phase with each other C. in phase with each other D. determined by load on transformer secondary

Last Answer : C. In phase with each other

Which of the following 3-phase connection of a transformer causes interference with the

Description : 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

The stator of phase shifting transformer for use in conjunction with an A.C. potentiometer usually has a?

Last Answer : The stator of phase shifting transformer for use in conjunction with an A.C. potentiometer usually has a two-phase winding.

A phase shifting transformer is used in conjunction with?

Last Answer : A phase shifting transformer is used in conjunction with Drysdale potentiometer.

Which type of winding is used in 3 phase shell-type transformer ?

Last Answer :  Sandwich type winding is used in 3 phase shell-type transformer.

Can Transformers develop Three Phase power from a Single Phase source?

Description : Can Transformers develop Three Phase power from a Single Phase source?

Last Answer : No. Phase converters or phase shifting devices such as reactors and capacitors are required to convert single phase power to three phase. 

What are two components of no load current in transformer?

Description : What are two components of no load current in transformer?

Last Answer : i) IM (Magnetizing/reactive /wattless) current. It magnetizes core ii) Iw (Coreloss/ active/wattful ) current. It supplies hysteresis and eddy current loss and negligible I² R loss.

What is Two winding transformer?

Description : What is Two winding transformer?

Last Answer : Two separate windings one as primary and other as secondary are used. Both windings are magnetically coupled.

What are the transformer losses?

Description : What are the transformer losses?

Last Answer : Answer: TRANSFORMER LOSSES - There are mainly two kinds of losses in a transformer namely 1. Copper loss (ohmic loss) and 2.magnetic loss (core loss). Copper losses are caused by the ... ohmic loss the following two losses are also present in the transformer stray load loss and dielectric loss.

At what power maximum efficiency of power transformer and distribution transformer is designed

Description : At what power maximum efficiency of power transformer and distribution transformer is designed

Last Answer : Maximum efficiency of the transformer is attained at certain load factor (α) when core losses of transformer is equal to the copper losses. PCore loss = α ^2 X PCopper loss From the ... the day. Hence distribution transformers are designed to have maximum efficiency at 50% of the rated full load

During No load why the power factor of the transformer is very low ?

Description : During No load why the power factor of the transformer is very low ?

Last Answer : Current flowing through the transformer consists of two components. Magnetizing current (Im) which is in quadrature (90 0 ) to the applied voltage and in phase current which is in phase to the applied voltage ... power factor of transformer during no load condition will by in the order of 0.1 to 0.2