Ham Radio General Class Practice Test

Which part of a transformer is normally connected to the incoming source of energy?

1. The secondary

2. The primary

3. The core

4. The plates

The correct answer is: The primary

In a transformer, the primary winding is the part that is connected to the incoming source of energy. This is where electrical energy is initially applied, usually from an alternating current (AC) power source. The magnetic field generated by the alternating current in the primary winding induces a voltage in the secondary winding through electromagnetic induction, which is the fundamental principle that allows transformers to function. The primary winding typically has a number of turns of wire that are designed to create a strong magnetic field when current flows through it, which provides the necessary energy transfer to the secondary winding. The design and turns ratio of the primary and secondary windings determine how the voltage is transformed, whether stepped up or stepped down, based on the needs of the electrical load on the secondary side. Other options do not relate to the connection of the incoming energy source in the same way. The secondary is the output side of the transformer, the core serves to concentrate the magnetic field and facilitate energy transfer between windings, and plates are not part of the basic transformer design related to energy input or output. Understanding this relationship within a transformer is crucial for efficient energy distribution in electrical systems.