No of electric field lines passing through a closed surface – unit Voltmeter
A transformer is an ideal device to relay current from primary to secondary. It works on the principle of induction created by the magnetic field of coiling.
A transformer works on the principle of magnetic induction. It consists of a winding that relays current from primary to secondary making a constant current. We have to provide a good conductor for magnetism because electricity needs a good conductor and to conduct magnetism, we need a good substitute that can retain and release magnetic property quickly.
Iron suitable best for magnetic properties:
While current flows into the primary winding, its magnetic field releases electricity quickly into the secondary coil. To conduct magnetism the same way in a matter of milliseconds, the process of magnetizing and demagnetizing must follow fast and iron is the best alternative to conduct it even better.
Since a solid iron core retains some magnet for some time, a laminated core is better suited for rapid magnetic shift because a solid core would hold on to the magnetism too well and not allow rapid magnetization or de-magnetization of the magnetic field built around it and rapid magnetic changes are required as the electricity switches polarity. Precisely a transformer works with electricity and magnetism combined.
Magnetism and electricity are closely related:
A transformer without either electricity or without magnet is incomplete. It works on the basis of magnetic induction. Therefore, when an electric current is passed through the primary, a magnetic field is created. The common core will induct to the primary magnetic field which couples with the secondary winding. Upon interruption in the primary current, its magnetic field will collapse but create a high voltage pulse that transfers to the secondary terminals as well through electromagnetic induction. The larger number of turns in the secondary will create high secondary voltage pulse maybe many thousands of volts. But to conduct good magnetism, we require a laminated core, because a solid core would hold on to the magnetism too well and not allow rapid magnetization and de-magnetization of the magnetic field that is built up, as the electricity switches polarity.
When we see a transformer, the Voltage ratio is the turns ratio when good metal conductor conducts between them, i.e: n1/n2= v1/V2. But the transformer will love its electric power if the connection between coil 1 and coil 2 does not induct properly.