All About Electromagnetic Induction Facts and Tutorials

Key Facts of Electromagnetic Induction

When a magnetic core is magnetized in a strong magnetic field, it retains magnetism after the magnetic force has been withdrawn. This phenomenon of lagging of induction flux density behind the magnetizing force is known as magnetic hysteresis. Moreover the same path is not followed during magnetization and demagnetization processes.

A Degaussing is the process of the demagnetizing metallic part.

Hysteresis can be reduced by the using grain oriented silicon steel.

According to Lenz's law the direction of induced electro motive force and hence current always opposes the cause producing it.

The time constant of an inductive circuit is defined as the ratio of L/R.

Air gap in the iron core of an inductive prevents linear law.

Sparking occurs when a load is switched off because the circuit has high inductance.

The growth of currents is an inductive circuit follows exponential law.

The mutual inductance of two coils is maximum when the coils are touching each other.

The coupling coefficient denotes the degree of magnetic linkage.

In electrical machines laminated cores are used with a view to reducing eddy current loss.

It is difficult to magnetize steel because of its low permeability.

Good Smoothing factor of a coil depends on the inductance of the coil.

The effect of the inductance of a coil on a constant direct current is that it does not effect the constant direct current.

The law that induces emf and current always opposes the cause producing them was discovered by the Lenz.

Leakage factor is more than unity.

A collapsing field around a coil tends to oppose the decay of coil current.

A conductor of length L has a current passing through it, when it is placed parallel to a strong magnetic field. The force experienced by the conductor will be zero.

The left hand rule, thumb correlates current, magnetic field and direction of force on a conductor.

While comparing magnetic and electric circuits, the flux of magnetic circuit is compared with the current electric circuit.

Whenever a conductor cuts magnetic flux. An emf is induced in that conductor. This statement is due to Faraday's law.

While comparing magnetic and electric circuits, the point of dissimilarity exists while considering is flux and current flow.