Question

A transformer works on:
A. DC only
B. AC only
C. Both AC and DC
D. High voltage only

Answer 1

Hint: First let us see what a transformer is:
A transformer is a static electrical system that transfers AC electrical power at a constant frequency from one circuit to the other circuit, but the voltage level may be modified to increase or decrease the voltage as desired.

Complete step by step answer:
- In the simplest way, a transformer can be represented as a thing that transforms. However, it is known as a static system that changes the degree of voltage between circuits when we learn more about it in-depth and in connection with electric current. The transformer is essentially a system for voltage control that is commonly used in alternating current power delivery and transmission.
- A transformer is a system used for the conversion of electrical energy to electricity. AC is the transmission current. It is widely used without a difference in the frequency of AC between circuits to raise or decrease the supply voltage. The transformer acts on simple electromagnetic induction and mutual induction concepts.
- The transformer type is widely used, and is graded as: based on voltage.
1. Step-up Transformer: Between the power generator and the power grid, they are used. There is a higher secondary output voltage than the input voltage.
2. Step Down Transformer: These transformers are used to convert the main high voltage input to the secondary low voltage output.
- The transformer works on the theory of the electromagnetic induction and mutual induction law of Faraday.
- The transformer core usually has two coils, a main coil and a secondary coil. In the shape of strips, the central laminations are joined in. High reciprocal inductance of the two coils.
- As per faraday's law of electromagnetic induction, when an alternating current passes through the primary coil, a changing magnetic flux develops and this shift of magnetic flux produces an emf (electromotive force) in the secondary coil which is attached to the centre having a primary coil. It is called mutual induction.

So, the correct answer is “Option B”.

Note:
Here we may be confused between AC and DC. But we should always remember that generators work on the principle of DC. The transformer only operates on ac supply since an alternating current is needed by a transformer that would produce a shifting magnetic field. In a coil, a changing magnetic field often produces a changing voltage. This is the basis of how a transformer works: an AC supply is hooked to the primary coil.