45 The function of conservator in a transformer is A. To protect against internal fault B. To reduce copper as well as core losses C. To cool the transformer oil D. To take care of the expansion and contraction of transformer oil due to variation of temperature of surroundings
Last Answer : D. To take care of the expansion and contraction of transformer oil due to variation of temperature of surroundings
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76 The changes in volume of transformer cooling oil due to variation of atmospeheric temperature during day and night is taken care of by which part of transformer? A. Conservator B. Breather C. Bushings D. Buchholz relay
Last Answer : A. Conservator
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1 answer

Last Answer : The function of breather in a transformer is to arrest flow of moisture when outside air enters the transformer.
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214 views
1 answer
asked
Mar 19, 2018
by
anonymous

What is conservator?
Last Answer : A conservator is a small cylindrical drum fitted just above the transformer main tank. It is used to allow the expansion and contraction of oil without contact with surrounding atmosphere. When conservator ... , the tank is fully filled with oil and the conservator is half filled with oil.
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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.
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136 views
1 answer
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May 22, 2020
by
anonymous

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
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May 22, 2020
by
anonymous

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.
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55 views
1 answer
asked
May 22, 2020
by
anonymous

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%.
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334 views
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May 22, 2020
by
anonymous

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
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2 answers
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May 17, 2020
by
anonymous

Single phase transformer
Last Answer : Single phase Transformer Transformer
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263 views
1 answer
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May 16, 2020
by
anonymous

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.
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160 views
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May 15, 2020
by
anonymous

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
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249 views
1 answer
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May 10, 2020
by
anonymous

Even at no-load, a transformer draws current from the mains. Why?
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Apr 28, 2020
by
anonymous

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.
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184 views
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asked
Jul 27, 2019
by
anonymous

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.
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137 views
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Jul 27, 2019
by
anonymous
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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
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1 answer
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Jul 26, 2019
by
anonymous

Last Answer : No-load current in a transformer lags behind the voltage by about 75°.
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91 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : The purpose of providing an iron core in a transformer is to decrease the reluctance of the magnetic path.
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210 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : In the transformer low voltage winding has got more cross-sectional area.
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259 views
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Mar 19, 2018
by
anonymous

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.
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364 views
1 answer
asked
Mar 19, 2018
by
anonymous
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Last Answer : Primary winding of a transformer could either be a low voltage or high voltage winding.
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87 views
1 answer
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Mar 19, 2018
by
anonymous
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Last Answer : High voltage winding in a transformer has more number of turns.
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368 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : The efficiency of a power transformer is of the order of 98 percent.
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104 views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : The no load current in a transformer lags behind the applied voltage by an angle of about 75°.
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190 views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : In a transformer, routine efficiency depends upon load current and power factor of load.
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136 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : The maximum efficiency of a distribution transformer is at 50% full load.
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143 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : Transformer breaths in when load on it decreases.
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91 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : No-load current of a transformer has small magnitude and low power factor.
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73 views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : The purpose of providing iron core in a step-up transformer is to decrease the magnitude of magnetizing current.
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552 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : The power transformer is a constant main flux device.
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63 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : In a transformer, the tappings are generally provided on low voltage side.
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93 views
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Mar 19, 2018
by
anonymous

Last Answer : The use of higher flux density in the transformer design reduces weight per kVA.
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126 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : The chemical used in breather for transformer should have the quality of cleansing the transformer oil.
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189 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : An ideal transformer has infinite values of primary and secondary inductances. The statement is false.
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329 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : The transformer ratings are usually expressed in terms of kVA.
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322 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : Material used for construction of transformer core is usually silicon steel.
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244 views
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Mar 19, 2018
by
anonymous

Last Answer : The thickness of laminations used in a transformer is usually 0.4 mm to 0.5 mm.
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98 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : A transformer oil must be free from moisture.
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68 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : Gas is usually not liberated due to dissociation of transformer oil unless the oil temperature exceeds 150°C.
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198 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : The main reason for generation of harmonics in a transformer could be saturation of core.
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129 views
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Mar 19, 2018
by
anonymous

Last Answer : Delta/star transformer works satisfactorily when on balanced as well as unbalanced loads.
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284 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : The magnetising current of a transformer is usually small because it has small air gap.
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80 views
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Mar 19, 2018
by
anonymous

Last Answer : The leakage flux in a transformer depends upon load current.
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319 views
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Mar 19, 2018
by
anonymous

Last Answer : Noise level test in a transformer is a type test.
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103 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : The core used in high frequency transformer is usually air core .
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220 views
1 answer
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Mar 19, 2018
by
anonymous

Last Answer : The full-load copper loss of a trans¬former is 1600 W. At half-load, the copper loss will be 400 W.
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149 views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : Power on primary and secondary side of transformer A. Remains Approximately constant B. Are always different C. Is always 100kVA D. None of these
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695 views
2 answers
asked
Mar 19, 2018
by
anonymous

Last Answer : High voltage winding of the transformer has less cross-sectional area.
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107 views
1 answer
asked
Mar 19, 2018
by
anonymous

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.
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76 views
1 answer
asked
Mar 19, 2018
by
anonymous

Last Answer : An ideal transformer is one which has no losses and magnetic leakage.
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232 views
1 answer
asked
Mar 19, 2018
by
anonymous
