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

1 Answer

Answer :

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

Related questions

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 : 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 : 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

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 : A ferrite core has less eddy current loss than an iron core because?

Last Answer : A ferrite core has less eddy current loss than an iron core because ferrites have high hysteresis.

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.

Description : A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is

Last Answer : Please show the solution for this question

Description : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?

Last Answer : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.

Last Answer : If the synchronous motor, properly synchronised to the supply is running on no load and is having negligible loss then the stator current will be zero.

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

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 : 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 : A transformer operates 24 hours day at full -load. It's full -load efficiency is :  (A) equal all day efficiency (B) more than all -day efficiency (C) less than all -day efficiency (D) equal to maximum efficiency

Last Answer : A transformer operates 24 hours day at full -load. It's full -load efficiency is : equal all day efficiency 

Description : A transformer has negative voltage regulation when its load power factor is   (1) Zero (2) Unity (3) Leading (4) Lagging

Last Answer : 0

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

Description : Select insulating materials for following parts : (i) Insulation between heating element and base plate of electric iron. (ii) Insulation used over copper or aluminium conductor used for making coils. (iii) Transformer bushings. (iv) Insulation between transmission line and pole.

Last Answer : Parts Insulating Materials  Insulation between heating element and base plate of electric iron. Mica Insulation used over copper or aluminium conductor used for making coils.  ... Transformer bushings Porcelain  Insulation between transmission line and pole. Porcelain

Description : Negative voltage regulation is indicative that the load is?

Last Answer : Negative voltage regulation is indicative that the load is capacitive.

Description : The efficiency of two identical transformers under load conditions can be determined by?

Last Answer : The efficiency of two identical transformers under load conditions can be determined by back-to-back test.

Description : Minimum voltage regulation occurs when the power factor of the load is?

Last Answer : Minimum voltage regulation occurs when the power factor of the load is leading.

Description : Even at no-load, a transformer draws current from the mains. Why?

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.

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 : Eddy current damping cannot be used for moving iron instrument because

Last Answer : Eddy current damping cannot be used for moving iron instrument because the presence of a permanent magnet required for such purpose would affect the deflection and hence the reading of the instrument

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

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

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

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

Description : The eddy current loss in a dc generator is 400 W at 40 Hz frequency of reversal and constant flux density. When frequency is increased to 50 Hz., eddy current loss is :  (A) 256 W (B) 320 W (C) 500 W (D) 625 W

Last Answer : The eddy current loss in a dc generator is 400 W at 40 Hz frequency of reversal and constant flux density. When frequency is increased to 50 Hz., eddy current loss is : 625 W

Description : Give the expression for ABCD constant of T model.

Last Answer : Expression for ABCD constants of T model: 

Last Answer : It is denoted as τ, tau and has the value of 1/RC. We

Description : Time constant for RC circuit formula τ = RC Where, τ = time constant

Last Answer : Time constant for RC circuit formula τ = RC Where, τ = time constant

Description : Define : i) Diffuse radiation ii) Beam radiation ii) Insolation iv) Solar constant

Last Answer : i) Diffuse radiation: It is the solar radiation which is scattered by the particles in earth's atmosphere and this radiation does not have any unique direction.  ii) Beam radiation: Solar radiation ... from the sun.  OR  It is the average radiation received outside the earth's atmosphere

Description : Define the term solar constant.

Last Answer : Solar energy arrived atmosphere at a constant rate of 1350W/M²

Description : What is meant by energy meter constant?

Last Answer : Energy Meter Constant  A fixed value which is used when converting meter readings to actual energy use, especially when potential transformers and similar types of equipment are used in metering. For example, K=--------rev/Kwh

Description : A transfer function has a second order denominator and constant gain in the numerator

Last Answer : A transfer function has a second order denominator and constant gain in the numerator the system has two zeros at infinity

Description : A dc chopper is fed from a constant voltage mains the duty ratio of chopper is progressively increased while the chopper feeds an RL load. The per unit current ripple would  (1) increase progressively  (2 ... 0.5 and then increase  (4) increase to a maximum value at α = 0.5 and then decrease

Last Answer : A dc chopper is fed from a constant voltage mains the duty ratio of chopper is progressively increased while the chopper feeds an RL load. The per unit current ripple would increase to a maximum value at α = 0.5 and then decrease