Methods Of Producing Electro Motive Force (EMF)
EMF can be generated using any one of the following three methods. These three methods are as follows:-(1) EMF can be produced by the use of chemical reactions such as primary and secondary cells.
(2) By heating the therm-confluence - EMF can also be produced by heating the thermocouple junction.
(3) EMF can also be produced by electromagnetic action. The electromagnetic induction method of generating EMF is the most important because only this method is used extensively for commercial production of electrical power.
By electromagnetic induction method emf can be generated by the following methods
(A) The emf is generated by moving the electric conductor in a constant magnetic field called a dynamically induced EMF. It is the principle on which a direct current generator works.
(B) EMF is generated in the conductor by treating the stationary conductor with a moving or rotational field having constant field strength. Used for all AC generators.
(C) EMF is generated in the conductor by the oscillation of the stationary conductor with variable magnetic field. In this, the conductor is not moving relative to the magnetic field. Hence the EMF thus generated is called a static induced EMF. The most important application of this method is in transformers, inspiratory coils, and spiraling coils.
Whenever a current carrying conductor is installed in a magnetic field, it experiences a mechanical force. On this principle, the direct motor works.
Direct current machines are mainly of two types-
(1) Direct current generator or dynamo.
By electromagnetic induction method emf can be generated by the following methods
(A) The emf is generated by moving the electric conductor in a constant magnetic field called a dynamically induced EMF. It is the principle on which a direct current generator works.
(B) EMF is generated in the conductor by treating the stationary conductor with a moving or rotational field having constant field strength. Used for all AC generators.
(C) EMF is generated in the conductor by the oscillation of the stationary conductor with variable magnetic field. In this, the conductor is not moving relative to the magnetic field. Hence the EMF thus generated is called a static induced EMF. The most important application of this method is in transformers, inspiratory coils, and spiraling coils.
Whenever a current carrying conductor is installed in a magnetic field, it experiences a mechanical force. On this principle, the direct motor works.
Direct current machines are mainly of two types-
(1) Direct current generator or dynamo.
(2) direct current motor
The structures of both machines are similar, but their working principle and operation are opposite to each other.