How is induced current in a secondary coil related to current in a primary coil and explain its principle?

An alternating current passes through a primary coil wrapped around a soft iron core. The changing current produces a changing magnetic field. This induces an alternating voltage in the secondary coil. This induces an alternating current (AC) in the circuit connected to the secondary coil.

What happens to the current in secondary coil when the current in the primary coil changes?

The primary must draw enough additional current to set up a field exactly equal and opposite to the field set up by the secondary current. The explanation says that when a load is attached to the secondary, the current in the primary must change to keep the applied voltage field the same.

How does the primary current increase as the current on secondary side of the transformer is increased?

The primary current increases as the secondary load current increases, and decreases as the secondary load current decreases. When the secondary load is removed, the primary current is again reduced to the small exciting current sufficient only to magnetize the iron core of the transformer.

What is the relationship between the voltages across the primary and secondary coils and their respective number of turns?

The voltage across the secondary coil is greater than the voltage across the primary. There are fewer turns on the secondary coil than the primary.

How EMF is induced in the secondary coil?

Transformers use changing magnetic fields to change the size of an alternating voltage. An alternating current passing in one coil (the primary) induces an e.m.f. in an adjacent coil (the secondary).

How is voltage induced in the secondary winding of a transformer?

When current is reduced, the magnetic field strength reduces. When the magnetic lines of flux flow around the core, they pass through the turns of the secondary winding, causing a voltage to be induced into the secondary coil.