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Flux linkages of an inductive circuit can not abruptly change.
Proof:- This can be proved by the logic of contradiction. Let the flux linkages abruptly change. Then by Laws of Electromagnetic induction infinite voltage is to be induced Infinity is conceptual and not practical. Hence the flux linkages cannot abruptly change in any practical sense. Hence the theorem.
Some discussion and limitations of the theorem:- Although Infinity cannot be brought forth into the practical world, it is conceptualized in a limiting process by defining Impulse function. Thus if impulse functions can be considered, the constant flux linkage theorem can be violated.
How to justify the word "Constant"?:- Considering a closed pure inductive circuit carrying a current I, it remains constant for ever, until infinity.
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Is mutual flux in transformer constant for all loads?
The flux is set by the voltage applied to the transformer. In most applications, the voltage is constant, and therefore the flux is constant also.
Why transformer is called constant flux machine?
when a load is connected to a transformer current(say I2) flows through secondary coil thus an M.M.F (N2I2) is produced ,this produces the secondary flux. This flux reduces the the main flux induced in the primary & also reduces E.M.F E1 in the primary As a result more current is drawn from the supply. This additional current drawn is due to the load component(say I2' ) This I2' is anti-phase with I2.This I2' sets a flux which opposes the secondary flux & helps the main flux. The load component flux neutralises the secondary flux produced by I2 .The M.M.F N1I2' balances N2I2.Thus the net flux is always at constant level. As practically flux is constant,the core loss is constant for all loads. Hence a transformer is always called a Constant Flux Machine.
Why induced emf alternates?
Here is A Simple answer for this question as you know that emf is induced in the conductor when there is change of flux linkage to the conductor which gives rise to the inducement of electric field in the conductor that provide drift velocity to the electrons hence emf is induced in the conductor but the last only till the change in flux in progress and becomes zero as soon as the flux linkages becomes constant hence we summaraize that for inducement of current there must be change in change of flux hence change in electric field that gives rise to allternating emf.
What are the differences between the natures of dc flux and ac flux?
dc flux is caused by dc current (flux and current are proportional), it is a constant value. Put an inductor (or transformer winding) across a battery and you will get dc flux. ac flux is caused by ac current (flux and current are proportional), it is a moving value, the flux moves with the current, typically cyclical but the waveform is arbitrary as long as we're moving.
Why do you have variation in leakage reactance of induction motor?
leakage reactance in induction motor depends on the reluctance of the path in which the leakage flux is establishing. with the increase in stator current the leakage flux also increases but it cannot maintain linear relationship because of saturation of the leakage flux path, even though current is increasing the flux will not increase and it'll be constant after saturation. this leakage flux links with the stator winding and induces emf which will be opposite to the supply voltage causes drop in applied voltage , the drop in the applied voltage is represented with the leakage reactance. as flux is responsible for the induction of emf , the increase in current does not increase flux after saturation and therefore emf also doesnot increase so the leakage reactance is not constant throughout the machine operation...
How do you determine the flux constant of a PMSM?
Flux linkage is determined by magnets. The constant flux (Wb) per pole pairs induced in the stator windings of the magnets. Flux established by the permanent magnets produce three trapezoidal back EMP waveforms.
Difference between flux linkage and flux leakage?
i) leakage flux is those flux which goes through the air and linkage flux is those flux whose go through the cell. ii)leakage flux is the loss at flux but linkage flu is warning flux. iii)leakage flux is cause of eddy current loss and linkage flux is case of copper loss.
What is the difference between magnetic flux magnetic flux densitymagnetic flux linkage?
light speeeed mofos
Why a double coil transformer does not work on a pure DC voltage source?
According to Faraday's Law only if there is change in flux linkage of a conductor then current is induced between mutual inductors. Now DC will induce a constant a constant flux in the transformer core, consequently in the secondary coil. So constant flux cannot induce a current in the secondary. SUBHRA JYOTI SAHA
Is mutual flux in transformer constant for all loads?
The flux is set by the voltage applied to the transformer. In most applications, the voltage is constant, and therefore the flux is constant also.
Flux in DC vary or constant.?
In DC or direct current, the flux is constant. AC or alternating current is variable.
Why does chokes require a core?
For better flux linkage and for least losses
Is there any device which can convert constant magnetic flux into variable flux?
A generator, in general.
Why transformer is called constant flux machine?
when a load is connected to a transformer current(say I2) flows through secondary coil thus an M.M.F (N2I2) is produced ,this produces the secondary flux. This flux reduces the the main flux induced in the primary & also reduces E.M.F E1 in the primary As a result more current is drawn from the supply. This additional current drawn is due to the load component(say I2' ) This I2' is anti-phase with I2.This I2' sets a flux which opposes the secondary flux & helps the main flux. The load component flux neutralises the secondary flux produced by I2 .The M.M.F N1I2' balances N2I2.Thus the net flux is always at constant level. As practically flux is constant,the core loss is constant for all loads. Hence a transformer is always called a Constant Flux Machine.
What is Gauss's theorem?
This theorem gives a relation between the total flux through any surface and net charge enclosed within the surface.
How do you improve the flux linkage between the primary and secondary windings in a transformer?
by using an iron core
Why is a transformer called constant flux machine?
when a load is connected to a transformer current(say I2) flows through secondary coil thus an M.M.F (N2I2) is produced ,this produces the secondary flux.This flux reduces the the main flux induced in the primary & also reduces E.M.F E1 in the primaryAs a result more current is drawn from the supply. This additional current drawn is due to the load component(say I2' )This I2' is anti-phase with I2.This I2' sets a flux which opposes the secondary flux & helps the main flux.The load component flux neutralises the secondary flux produced by I2 .The M.M.F N1I2' balances N2I2.Thus the net flux is always at constant level.As practically flux is constant,the core loss is constant for all loads.Hence a transformer is always called a Constant Flux Machine.
