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it is the force experienced by a north pole of strength 'p' placed at a distance 'd' meters from another pole of strength 'm'in a medium of relative permeability.
in a steel nail there are these things called domains, in a weakly magnetized nail some of them will be pointing north, south, east and west, but however in a strongly magnetized nail all the domains will point to north.
What else can I help you with?
What are compensating winding?
compensating windings are used to overcome armature reaction
How power factor is related to air gap?
Lesser air gap, less is the magnetising current (which is lagging reactive component of current)causing better p.f.
Why open circuit test show only core losses?
With the secondary not supplying any load, there is no secondary current and the primary current will be a low-value magnetising current. So, the copper losses, (I2R) will be insignificant.
Magnetising characteristics of DC shunt generator?
the magnetizing curve is the relation b/w air gap flux and the field winding current armature EMF. the resulting curve is called magnetizing characteristics or open circuit characteristics. at any speed by recognizing that the induced emf is directly proportional to the speed
Is core loss same as no load loss in transformer?
Yes, that is almost true, apart from a very small copper loss in the primary winding that carries the small magnetising current. The core loss (iron loss) depends on the applied voltage. This loss is measured by the open-circuit test, carried out at the working voltage.
What is the magnetising force?
its a force that moves by electric current
Does magnetising metal accelerate rusting?
Yes
What are precommissioning tests of transformers?
magnetising current test, magnetising balance test, s.c test, vector group test, winding resistance test, ratio test
What are the factors that increase the magnetising force of an electromagnet?
-- diameter of the current-carrying winding around it -- number of turns of wire in the winding -- magnitude of the current in the winding -- material comprising the core of the magnet
What is full load magnetising current of transformer?
is it primary current ?
Why flux must lag the applied voltage by 90degrees in transformers?
It's not a matter of 'must'; it's a natural phenomenon. Because of the very high inductance, the magnetising current lags the supply voltage by 90 degrees and the magnetic flux is in phase with the magnetising current.
What are compensating winding?
compensating windings are used to overcome armature reaction
What is the use of novoltreleasecoil in starters?
no volt release coil is use for basicali magnetising & when over current is flowing it will demagnetising propus
Sketch and explain the no load phasor diagram of a transfomer?
a.) Io = no load current consists of 5% of the full-load primary current. b.) Iom = magnetising current/component responsible for setting up the magnetising flux in the core. c.) Iol = Ic = power loss component responsible for supplying the core losses and the windings losses.
What is real power in electricity?
real power is to do do work and it is supplied to the load ,where as the reactive power is used for magnetising and the apparent power is the total power
The effects of reluctance and hysteresis with respects towards the magnetic circuits?
You can compare a magnetic circuit to an electric circuit, wheremagnetomotive force is equivalent to electromotive forceflux is equivalent to currentreluctance is equivalent to resistanceFor a magnetic circuit, the equivalent of Ohm's Law is: flux = mmf/reluctance.So, for a given value of magnetomotive force, the greater the reluctance, the lower the resulting flux. For example, iron will have a very low value of reluctance whereas air will have a very very high reluctance, so if a magnetic circuit has an airgap, then the overall reluctance of the circuit will be far greater than for a magnetic circuit without an airgap.Hysteresis comes from a Greek word, meaning to 'lag behind'. It describes how a magnetic circuit's flux density behaves when it is continuously magnetised and demagnetised. For example, when we apply a magnetising force, the flux density increases but, if we then remove the magnetising force, some flux density remains and, in order to remove this, we need to apply a magnetising force in the opposite direction. The amount of flux density remaining after we remove the magnetising force is called 'retentivity' and, for materials such as steel, this is quite large; but for other materials, such as iron, this is very small. So, hysteresis is a way of describing whether a metal is going to be suitable for use as a permanent magnet or for use as a temporary magnet. In particular, we need to understand the significance of hysteresis when choosing a suitable metal to manufacture transformer cores or motor magnetic circuits.
How do you make metal attractive?
Attractive as in magnetism or as in beauty? Polish will make it attractive to the eye, magnetising it will make certain metals attract ferrous items.
