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Flux incresed with the increase of scalar quantity
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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...
Why the series motor is started with some minimum load?
In series motor, At no Load Condition the flow of Armature Current is low, then the Flux is also low. Flux is inversely proportional to speed. If flux is decrease the speed is rapidly increase it spoil the rotor parts...... so SERIES MOTOR is start with LOAD.....
Difference between leakage flux and mutual flux?
when a current flow through the coil then flux produced around the coil . if the flux linked same produced coil only then the flux is said to be leakage flux. flux produced by one coil ,but linked with another coil then the flu is said to be mutual flux.
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 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 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...
Why should the flux density increase with the speed of the magnets?
It is because induction of electricity depends on rate of change of flux and it means the speed of magnet
In transformer core flux depends on voltage whereas leakage flux depends on current?
In a Transformer, Core flux is the difference of primary flux and Secondary flux which are opposite to each other in direction. There difference is equal to the no load flux at all loads. So, some of primary flux passes through the core and remaining becomes leakage flux (Because Secondary flux forces it to get out of the core). Same is the case with Secondary flux. Now, flux is directly proportional to Voltage and Current. When Current increases due to increased load (and voltage remains same): Then both primary and secondary flux increase. Because both of them increase, so there difference remains same. And all remaining flux is forced out. Hence leakage flux increases with current, but Core flux remains constant. When Primary Voltage is increased: Then only primary flux increases. So difference of this new increased primary flux and previous same secondary flux increases. Hence Core flux increases with voltage, But leakage flux does not. That's how In transformer core flux depends on voltage whereas leakage flux depends on current.
What will be cosmic ray flux at poles and equator?
Cosmic rays flux at high latitudes are almost 20% more than at equator, from 60° to 90° of latitude none increment due to rigidity cutoff. The flux also increase with altitude.
If two induction motors have same ratings except that one is designed for 50Hz and the other for 60Hz then which one will have larger size and why?
the motor with frequency 60Hz will be larger. As frequency is inversly proportional to the flux, now for 60 Hz the flux will be small and it will be not enough to give us the required output (given that output of both motors are also equal), so to increase the flux we will increase number of tuns of stator's winding and hence the machine's size will increase.
Why the series motor is started with some minimum load?
In series motor, At no Load Condition the flow of Armature Current is low, then the Flux is also low. Flux is inversely proportional to speed. If flux is decrease the speed is rapidly increase it spoil the rotor parts...... so SERIES MOTOR is start with LOAD.....
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 limit for magnetic field developed for a DC machine?
The magnetic field used in machines is quantified in terms of its flux density (symbol: B), expressed in teslas. The flux density is established by the magnetic field strength (H), expressed in amperes per metre, set up in the field windings.As the magnetic field strength increases, the flux density increases until it reaches saturation. This is the point when the magnetic domains within the magnetic circuit are all aligned. At this point, any further increase in magnetic field strength will fail to increase the flux density.So saturation of the magnetic circuit limits the flux density of the field.
What is leakage factor?
The Ratio of the total flux ( flux in iron path) to the useful flux (flux in air gap)
Why does the slope of the saturation curve level off towards the top?
• Since the unsaturated core of the machine has a reluctance thousands times lower than the reluctance of the air-gap, the resulting flux increases linearly first. When the saturation is reached, the core reluctance greatly increases causing the flux to increase much slower with the increase of the mmf.
How are the energy and wavelength of electro magnetic radiation related?
The Relationship is the 'Flux' of the magnetic field.Changing the amount of energy will not effect the wavelength (except to choke off the field when it becomes too dense)and increasing the wavelength will increase the energy density (flux)
Difference between leakage flux and mutual flux?
when a current flow through the coil then flux produced around the coil . if the flux linked same produced coil only then the flux is said to be leakage flux. flux produced by one coil ,but linked with another coil then the flu is said to be mutual flux.
