CAMRT Radiography Practice Exam

Transformers operate on which principle?

1. Direct induction

2. Reciprocal induction

3. Mutual induction

4. Self induction

The correct answer is: Mutual induction

Transformers operate on the principle of mutual induction. This principle involves the process in which a changing magnetic field in one coil induces a voltage in another nearby coil. When alternating current passes through the primary winding of a transformer, it creates a varying magnetic field. This varying magnetic field induces an electromotive force (EMF) in the secondary winding of the transformer through mutual coupling. In practical terms, this means that transformers can efficiently transfer energy between circuits at different voltage levels without direct electrical connection between them. The effectiveness of mutual induction is enhanced by the physical proximity and the magnetic core that directs the magnetic flux from the primary to the secondary coil. This principle is fundamental in designing transformers used in power distribution and electrical appliances, highlighting the essential nature of mutual induction in electrical theory and applications. Other principles, such as self-induction, which refers to a coil inducing a voltage within itself due to changes in its own current, do not describe the operation of transformers as they relate to multiple coils working together.