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Answer :

The full-load copper loss of a trans¬former is 1600 W. At half-load, the copper loss will be 400 W.

Related questions

Description : Full load copper loss in a transformer is 1600 watts. At half load the copper loss will be: A) 6400 watt B) 1600 watt C) 800 watt D) 400 watt

Last Answer :  Full load cupper loss in a transformer is 1600 watts. At half load the cupper loss will be: 400 watt

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.

Description : A 40 kVA transformer has a core loss of 400 W and a full load copper loss of 800 W. The proportion of full load at maximum efficiency is

Last Answer : A 40 kVA transformer has a core loss of 400 W and a full load copper loss of 800 W. The proportion of full load at maximum efficiency is 0.707

Description : At full -load of a transformer, the iron loss and copper loss are 3000 W and 4000 W respectively. Then total loss at maximum efficiency is :  (A) 7000 W (B) 6000 W (C) 8000 W (D) 4000 W

Last Answer : At full -load of a transformer, the iron loss and copper loss are 3000 W and 4000 W respectively. Then total loss at maximum efficiency is : 6000 W

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

Last Answer : The no load current in a transformer lags behind the applied voltage by an angle of about 75°.

Last Answer : No-load current of a transformer has small magnitude and low power factor.

Last Answer : An ideal transformer will have maximum efficiency at a load such that copper loss equal to iron loss.

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.

Description : For a transformer, operating at constant load current, maximum efficiency will occur at?

Last Answer : For a transformer, operating at constant load current, maximum efficiency will occur at unity power factor.

Description : The maximum load that a power transformer can carry is limited by its?

Last Answer : The maximum load that a power transformer can carry is limited by its voltage ratio.

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.

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

Last Answer : In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of less than 15A.

Description : 40 No load test on a transformer is carried out to find A. Copper loss B. magnetising current C. Magnetising current and loss D. Efficiency of the transformer

Last Answer : C. Magnetising current and loss

Description : 22 No load test on a transformer is carried out to find A. copper loss B. magnetising current C. Magnetising current and no load loss D. Efficiency of the transformer

Last Answer : C. Magnetising current and no load loss

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

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

Description : 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

Last Answer : A. 1600

Description : A 500 kVA, 3-phase transformer has iron losses of 300 W and full load copper losses of 600 W. The percentage load at which the transformer is expected to have maximum efficiency is  (A) 50.0% (B) 70.7% (C) 141.4% (D) 200.0%

Last Answer : A 500 kVA, 3-phase transformer has iron losses of 300 W and full load copper losses of 600 W. The percentage load at which the transformer is expected to have maximum efficiency is 70.7%

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.

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

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.

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%.

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

Description : Single phase transformer

Last Answer : Single phase Transformer 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. 

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

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.

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.

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

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

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

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.

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

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

Last Answer : The efficiency of a power transformer is of the order of 98 percent.

Last Answer : In a transformer, routine efficiency depends upon load current and power factor of load.

Last Answer : The maximum efficiency of a distribution transformer is at 50% full load.

Last Answer : Transformer breaths in when load on it decreases.

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

Last Answer : The power transformer is a constant main flux device.

Last Answer : In a transformer, the tappings are generally provided on low voltage side.

Last Answer : The use of higher flux density in the transformer design reduces weight per kVA.

Last Answer : The chemical used in breather for transformer should have the quality of cleansing the transformer oil.

Last Answer : An ideal transformer has infinite values of primary and secondary inductances. The statement is false.

Last Answer : The transformer ratings are usually expressed in terms of kVA.

Last Answer : Material used for construction of transformer core is usually silicon steel.

Last Answer : The thickness of laminations used in a transformer is usually 0.4 mm to 0.5 mm.

Last Answer : conservator or a reservoir tank for insulating oil in transformer which used for balanced the onload oil level with help of oil level indicator which mount on middle part of reservoir tank.

Last Answer : A transformer oil must be free from moisture.