Question

A transformer is a device which gives:
A.DC voltage
B.AC voltage
C.Both DC and AC voltage
D.None of these

Answer 1

Hint: in this question, we will discuss the basics of transformers and the working of transformers. This will give us the required answer. Further, we will also see the losses in transformers and an ideal transformer, for our better understanding of the topic.

Complete answer:
As we know a transformer is a device, which is used for stepping up or stepping down, the voltage of an alternating electrical signal.
It can also be defined as a static electrical machine which transfers alternating electrical power from one circuit to the other circuit at a constant frequency. Here, when we say voltage level can be altered that means voltage can be increased or decreased according to our requirement.

Therefore, the correct option is B) i.e., a transformer is a device which gives only AC voltage.

Additional information:
As we know the basic idea of a transformer was first discussed by Michael Faraday in the year 1831. His idea was further carried by many other prominent scientific scholars.
Here, we need to know that a transformer works on the principle of Faraday’s law of electromagnetic induction and mutual induction.
 When we learn about the working of a transformer, we can see that there are generally two coils, known as primary coil and secondary coil on the transformer core. The core laminations are joined in the form of strips. The two coils have high mutual inductance. Now when an alternating current or AC passes through this primary coil, it forms a varying magnetic flux as given by Faraday’s law of electromagnetic induction. So, this change in magnetic flux induces an electromotive force or emf in the secondary coil which is linked to the core having a primary coil. This is called mutual induction.
Now, if we want to remember in short terms, a transformer carries the below operations:
Transfer of electrical energy takes place from the circuit to another
Transfer of the electrical power through electromagnetic induction
Electric power is transferred without any change in frequency of the signal
The two circuits present here, are linked with mutual induction

Note:
We should remember that transformers experience some losses in the form of magnetic leakage and windings. Also, an ideal transformer has no losses that means there is no magnetic leakage and ohmic resistance in its windings of circuits and wires.