## Practical transformer

Practical transformer is different from ideal transformer in many respects. Ideal transformer has no losses but practical transformer have

- Iron losses
- Magnetic leakage
- Winding resistances

**Ideal transformer on no load**

A transformer is ideal if it has

- No leakage flux
- No windings resistance
- No iron loss in core

Ideal transformer can not possible physically. But it gives powerful tool in the analysis of a practical transformer. Properties of ideal and practical transformer is very close each other.

The efficiency of electrical power transmission has improved for using higher voltages. Alternating current has entirely replaced by the direct current for power transmission and distribution. For producing higher voltages ac generator is better than dc generator.

Transformer is an electrical device for transferring electrical energy one circuit to another circuit without changing frequency. It is widely using in alternating current now a days.

An inductor is a passive two terminal element designed to store energy in its magnetic field. Inductor also called reactor or coil. It consists of conductor like wire wound into a coil. When current passing through the coil, energy is stored temporarily into the magnetic field. Applications of inductor in our daily life are transformers, power supplies, TVs, radios, radars etc.

A capacitor is an element which stores charges. It is a passive element as it stores energy. Michael Faraday invented capacitor. The unit of capacitance is Farad was the name of honor of Michael Faraday. In electronics, communication, power systems, computer etc field capacitors are extensively used. In circuit capacitor in an important circuit element, its role can not be described in words.

Linear property is the linear relationship between cause and effect of an element. This property gives linear and nonlinear circuit definition. The property can be applied in various circuit elements. The homogeneity (scaling) property and the additivity property are both the combination of linearity property.

Sometimes we are not sure in electric circuits that the resistors are neither in parallel nor in series.

See the circuit below here the relation between R_{1} resistor and R_{6} resistor is series or parallel we are not sure.

When a circuit has two or more independent sources, we can determine the contribution of each source applying nodal analysis or mesh analysis. Another way is to find out the contribution of the independent sources (voltage or current) is to apply superposition theorem.

Superposition theorem is based on circuit linearity property.