Question

The transformer is used in ................. current circuits.

• A. alternating
• B. directing
• C. no
• D. less

Answer 1

The correct option is A alternating

A transformer consists of two coils - the primary coil and the secondary coil both wound on a soft iron core. If an ac voltage is applied to the primary coil then this will produce a changing magnetic field in the iron core. This induces an alternating voltage in the secondary coil according to electromagnetic induction.
A voltage in the secondary coil occurs only if the magnetic field is changing. Therefore, transformers will only work with ac current only. The transformer is used in alternating current circuits.