Which of the following is NOT a component of an electrical panel?

Transformers are not a component of an electrical panel. An electrical panel, also known as a breaker panel or service panel, is primarily designed to distribute electricity throughout a building and manage the electrical system. The key components of an electrical panel include circuit breakers, which protect the wiring and prevent overloads by shutting off the circuit when too much current flows; fuses, which serve a similar protective function by melting a wire when excess current flows, thus interrupting the circuit; and bus bars, which are conductive bars that distribute electrical current to multiple circuits.

Transformers, on the other hand, are devices used to change the voltage level of electricity and are typically located outside the panel or at the service entrance. They provide the necessary voltage transformation for various uses, such as stepping down high voltages for residential use. Since the primary function of an electrical panel is electrical distribution and protection rather than voltage transformation, the inclusion of a transformer would not be standard in a conventional panel setup.