Red Seal Industrial Electrician Practice Exam

What is the primary function of a transformer in an electrical distribution system?

1. To change the frequency of AC circuits

2. To change the voltage level while maintaining power

3. To convert DC to AC voltage

4. To store electrical energy for later use

The correct answer is: To change the voltage level while maintaining power

The primary function of a transformer in an electrical distribution system is to change the voltage level while maintaining power. Transformers operate based on the principles of electromagnetic induction, allowing them to increase (step-up) or decrease (step-down) voltage levels. This ability is crucial in power distribution systems, as it enables efficient long-distance transmission of electrical energy. When the voltage is increased, the current decreases, which minimizes energy loss due to heat in the conductors. In contrast, at the point of use, the lower voltage ensures safety and compatibility with devices and equipment. Maintaining power during this transformation is vital. While the transformer changes the voltage, the relationship between power (voltage multiplied by current) remains consistent, minus minor losses in efficiency. Thus, the functionality of a transformer allows for the safe and efficient distribution and utilization of electrical energy throughout various applications in the grid and industrial settings.