Question

What type of voltage does a transformer give?

Answer 1

Hint: A transformer works on the principle of mutual induction. A change in current in the primary coil produces a change in the magnetic flux linked with the secondary coil thus induces an EMF in the secondary coil. An AC voltage provides alternating current and DC voltage provides constant current.

Complete step by step answer:
A transformer is a device that transfers electrical energy from one circuit to another by using the process of electromagnetic induction. It is used to increase voltage level or decrease voltage level between circuits.
There are four primary parts to a basic transformer. An input connection ,output connection ,core and the windings. Transformers have two windings, the primary winding and the secondary winding. The number of turns in the primary winding is represented as ${N_P}$ and the number of turns in the secondary winding is represented as ${N_S}$. Voltage given to the primary winding is denoted as ${V_P}$ and voltage that we get at the secondary winding is denoted as ${V_S}$. The transformer equation is given by
$\dfrac{{{V_P}}}{{{V_S}}} = \dfrac{{{N_P}}}{{{N_S}}}$
Principle of transformer: A transformer works on the principle of mutual induction. When there is a change in current in the primary coil the magnetic flux linked with the secondary coil changes which induces an EMF in the secondary coil.
The working of the transformer itself depends on change in current in the primary coil. The DC provides a constant current. Thus, it cannot produce a varying magnetic field. Therefore, EMF cannot be induced in the secondary coil

Hence a transformer can work only on AC and the output is also an AC voltage which will be stepped up or down depending upon the number of turns in the primary and secondary coil. Output voltage can be calculated using the transformer equation.

Note:
Transformer can be used both as a step up transformer and step down transformer. In step up transformers we get a higher AC voltage at the output than the input AC voltage. In such a type of transformer, the number of turns in the secondary winding will be greater than the number of turns in the primary winding. In the step down transformer we get a low AC voltage at the output. In such a transformer number of turns in the secondary winding will be less than the number of turns in the primary winding