During short circuit test iron losses are negligible because?

During short circuit test iron losses are negligible because?

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Answer :

During short circuit test iron losses are negligible because the voltage applied on primary side is low.

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Related questions

[53] The iron loss of the transformer is negligible during short circuit test because A. The entire input is just sufficient to meet Cu losses only B. Flux produced is a small fraction of the normal flux C. Iron core becomes fully saturated D. Supply frequency is held constant

Description : [53] The iron loss of the transformer is negligible during short circuit test because A. The entire input is just sufficient to meet Cu losses only B. Flux produced is a small fraction of the normal flux C. Iron core becomes fully saturated D. Supply frequency is held constant

Last Answer : B. Flux produced is a small fraction of the normal flux

During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer

Description : During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer

Last Answer : C) the voltage applied on primary side is low

During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer

Description : During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer

Last Answer : C) the voltage applied on primary side is low

[75] Two transformers are connected in parallel. These transformers do not have equal percentage impedance which results A. Short-circuiting of the secondaries B. Power factor of one of the transformers is leading while that of the other lagging C. Transformers having higher copper losses will have negligible core losses D. Loading of the transformers not in proportion to their kVA ratings.

Description : [75] Two transformers are connected in parallel. These transformers do not have equal percentage impedance which results A. Short-circuiting of the secondaries B. Power factor of one of the ... have negligible core losses D. Loading of the transformers not in proportion to their kVA ratings.

Last Answer : D. Loading of the transformers not in proportion to their kVA ratings

64)During the short-circuit test on a small transformer the frequency is increased from 50-200Hz. The copper losses will increase by a factor of A. 16 B. 4 C. 1 D. 1/4

Description : 64)During the short-circuit test on a small transformer the frequency is increased from 50-200Hz. The copper losses will increase by a factor of A. 16 B. 4 C. 1 D. 1/4

Last Answer : A) 16

7 The main advantage of auto transformer over a two winding transformer is A. Hysteresis losses are reduced B. Saving in winding material C. Copper losses are negligible D. Eddy losses are totally eliminated

Description : 7 The main advantage of auto transformer over a two winding transformer is A. Hysteresis losses are reduced B. Saving in winding material C. Copper losses are negligible D. Eddy losses are totally eliminated

Last Answer : A) hysteresis losses is reduced

During open circuit test of a transformer?

Description : During open circuit test of a transformer?

Last Answer : During open circuit test of a transformer primary is supplied rated voltage.

Reduction in core losses and increase in permeability are obtained with transformer employing?

Description : Reduction in core losses and increase in permeability are obtained with transformer employing?

Last Answer : Reduction in core losses and increase in permeability are obtained with transformer employing core built-up of laminations of cold rolled grain oriented steel.

In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are?

Description : In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are?

Last Answer : In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are hysteresis and eddy current losses.

An open-circuit test on a transformer is conducted primarily to measure?

Description : An open-circuit test on a transformer is conducted primarily to measure?

Last Answer : The open-circuit test in a transformer is used to measure

The secondary of a current transformer is always short-circuited under operating conditions because it?

Description : The secondary of a current transformer is always short-circuited under operating conditions because it?

Last Answer : The secondary of a current transformer is always short-circuited under operating conditions because it avoids core saturation and high voltage induction.

In an actual transformer the iron loss remains practically constant from no load to full load because?

Description : In an actual transformer the iron loss remains practically constant from no load to full load because?

Last Answer : In an actual transformer the iron loss remains practically constant from no load to full load because core flux remains practically constant.

Equivalent circuit of transformer

Description : Equivalent circuit of transformer

Last Answer : Equivalent Circuit Diagram of Transformer Referred to Primary: V1 -Primary Input voltage I1 - Input Current I0- Exciting current/ No load current Im- Magnetizing component ... equivalent of secondary terminal voltage ZL- Load impedance ZL ′- Primary equivalent of load impedance

The purpose of providing an iron core in a transformer is to?

Last Answer : The purpose of providing an iron core in a transformer is to decrease the reluctance of the magnetic path.

The purpose of providing iron core in a step-up transformer is?

Last Answer : The purpose of providing iron core in a step-up transformer is to decrease the magnitude of magnetizing current.

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.

Iron loss of a transformer can be measured by?

Last Answer : Iron loss of a transformer can be measured by low power factor wattmeter.

When secondary of a current transformer is open-circuited its iron core will be?

Description : When secondary of a current transformer is open-circuited its iron core will be?

Last Answer : When secondary of a current transformer is open-circuited its iron core will be hot because of heavy iron losses taking place in it due to high flux density.

Noise level test in a transformer is a?

Last Answer : Noise level test in a transformer is a type test.

A no-load test is performed on a transformer to determine?

Description : A no-load test is performed on a transformer to determine?

Last Answer : A no-load test is performed on a transformer to determine magnetizing current and loss.

Sumpner's test is conducted on transformer to determine?

Description : Sumpner's test is conducted on transformer to determine?

Last Answer : Sumpner's test is conducted on transformer to determine temprature.

48.During light loads, the transformer efficiency is low because A. Secondary output is low B. Transformer losses are high C. Fixed loss is high in proportion to the output D. Cu loss is small

Description : 48.During light loads, the transformer efficiency is low because A. Secondary output is low B. Transformer losses are high C. Fixed loss is high in proportion to the output D. Cu loss is small

Last Answer : C. Fixed loss is high in proportion to the output

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.

The magnetising current of a transformer is usually small because it has?

Last Answer : The magnetising current of a transformer is usually small because it has small air gap.

The efficiency of a transformer, under heavy loads, is comparatively low because?

Description : The efficiency of a transformer, under heavy loads, is comparatively low because?

Last Answer : The efficiency of a transformer, under heavy loads, is comparatively low because copper loss becomes high in proportion to the output.

Why are iron losses considered as constant losses in transformer?

Description : Why are iron losses considered as constant losses in transformer?

Last Answer : Iron losses depend on supply frequency and flux density in the core. For all normal operations, the frequency of flux reversals which is same as supply frequency is constant and the value of flux density ... . Hence iron losses remain constant under all load conditions. i-e from no-load to full-load

43 The purpose of providing an iron core in a transformer is to A.Provide support to windings B. Reduce hysteresis loss C. decrease the reluctance of the magnetic path D. reduce eddy current losses

Description : 43 The purpose of providing an iron core in a transformer is to A.Provide support to windings B. Reduce hysteresis loss C. decrease the reluctance of the magnetic path D. reduce eddy current losses

Last Answer : C. Decrease the reluctance of the magnetic path

42 The efficiency of a transformer will be maximum when A. copper losses = hysteresis losses B. Hysteresis losses = eddy current losses C. Eddy current losses = copper losses D. Copper losses = iron losses

Description : 42 The efficiency of a transformer will be maximum when A. copper losses = hysteresis losses B. Hysteresis losses = eddy current losses C. Eddy current losses = copper losses D. Copper losses = iron losses

Last Answer : D. Copper losses = iron losses

1 Sumpner's test is conducted on transformers to find A. Temperature B. Stray losses C. All-day efficiency D. None of the above

Description : 1 Sumpner's test is conducted on transformers to find A. Temperature B. Stray losses C. All-day efficiency D. None of the above

Last Answer : A. Temperature

What is determined from short circuit test?

Description : What is determined from short circuit test?

Last Answer : Copper loss

66 While conducting short-circuit test on a transformer the following side is short circuited A. High voltage side B. low voltage side C. primary side D. secondary side

Description : 66 While conducting short-circuit test on a transformer the following side is short circuited A. High voltage side B. low voltage side C. primary side D. secondary side

Last Answer : B. Low voltage side

30 In performing the short circuit test of a transformer A. high voltage is usually short circuited B. low voltage side is usually short circuited C. any side is short circuited with preference D. none of the above

Description : 30 In performing the short circuit test of a transformer A. high voltage is usually short circuited B. low voltage side is usually short circuited C. any side is short circuited with preference D. none of the above

Last Answer : B. Low voltage side is usually short circuited

what is short circuit test in transformer?

Last Answer : In short circuit test of transformer the low voltage side is short circuited . On high voltage side the voltmeter is connected in parallel and ammeter in series and also a wattmeter is ... circuit test is done for determining impedance and losses. In this test iron losses is neglected.

Atmospheric temperature during day and night is taken care of by which part of the transformer?

Description : The changes in the volume of transformer cooling oil due to the variation of atmospheric temperature during day and night is taken care of by which part of the transformer?

Last Answer : The changes in the volume of transformer cooling oil due to the variation of atmospheric temperature during day and night is taken care of by conservator.

Explain the effect of Harmonics on the Transformer.

Description : Explain the effect of Harmonics on the Transformer.

Last Answer : Effect of Harmonics on the Transformer:  1. Core loss: Harmonic voltage increases the hysteresis and eddy current losses in the lamination. The amount of the core loss depends on ... small core vibrations.  5. Saturation problem: Sometimes additional harmonic voltage causes core saturation.

List two special feature of welding transformer.

Description : List two special feature of welding transformer.

Last Answer : Special features of welding transformer: i) It is a step down transformer that reduces the source voltage to a voltage desired according to the demands of the welding process. ii) Having large primary turns and less ... V ii) Secondary voltage - 40 to 60 V iii) Secondary current - 200 to 600 A

State two applications of isolation transformer

Description : State two applications of isolation transformer

Last Answer : Applications of isolation transformer: i) Isolates the load equipment from supply ground: ii) Reduction of voltage spikes iii) It acts as a decoupling device. iv) Protects loads from harmonic distortion.

State why a transformer always have an efficiency of more than 90%.

Description : State why a transformer always have an efficiency of more than 90%.

Last Answer : As transformer is static device with no moving parts, the losses due to friction & windage are completely absent. Hence transformer has efficiency of more than 90%.

Single phase transformer

Description : Single phase transformer

Last Answer : Single phase Transformer Transformer

What is the use of transformer?

Description : What is the use of transformer?

Last Answer : The use of transformer  is to do lower or raise  the voltage or currents in an electrical  circuit.  That's quite so simple. 

Transformer on DC

Description : Write about transformer on DC.

Last Answer : Transformer on DC : Transformer cannot work on DC. Transformer works on electromagnetic induction principle. Electromagnetic induction principle means when flux linking with coil changes and EMF induced in it ... winding insulation will burn. https://youtu.be/TVp_0fIfxqY

State and justify which of the following two transformers is better: Transformer A = 4% voltage regulation Transformer B = 6% voltage regulation

Description : State and justify which of the following two transformers is better:  Transformer A = 4% voltage regulation  Transformer B = 6% voltage regulation

Last Answer : Transformer A with 4% voltage regulation is better.  Justification: Voltage regulation refers to the percentage change in secondary voltage when load is changed from no-load to full-load with primary voltage ... 4% voltage regulation, which is less as compared to 6% of transformer B, it is better.

State any four characteristics of core type transformer.

Description : State any four characteristics of core type transformer.

Last Answer : Characteristics of core type transformer: i) It has one window. ii) It has one magnetic circuit. iii) Core surrounds the winding. iv) Average length of core is more. v) Area of cross ... Better cooling for winding. vii) Mechnical strength is comparatively less. viii) Repair and maintenance is easy.

Explain construction and working of single phase Auto transformer.

Description : Explain construction and working of single phase Auto transformer.

Last Answer : Construction of single phase auto transformer: (i) It has only one winding wound on a laminated circular magnetic core. (ii) The core is made of silicon steel stampings. (iii) The two terminals of the ... help of handle. 5) The same transformer can be used as step-up or step down auto-transformer

No-load current in a transformer?

Last Answer : No-load current in a transformer lags behind the voltage by about 75°.

In the transformer which winding has got more cross-sectional area?

Last Answer : In the transformer low voltage winding has got more cross-sectional area.

Primary winding of a transformer?

Last Answer : Primary winding of a transformer could either be a low voltage or high voltage winding.

Which winding in a transformer has more number of turns ?

Last Answer : High voltage winding in a transformer has more number of turns.