TSA Electrical Applications Practice Test 2025 - Free Electrical Applications Practice Questions and Study Guide

The component that typically controls the flow of electric current in a circuit is a transistor. Transistors are semiconductor devices that can amplify and switch electronic signals and electrical power, making them fundamental in modern electronic devices. They function as electronic switches or gates, enabling or preventing the flow of current through the circuit.

Transistors can be used to control large currents with smaller input currents, which is crucial in various applications, including signal modulation and power regulation. Their ability to control current flow is essential in processes like amplification, where a small input signal is converted into a larger output signal, and in digital circuits where they represent logical operations.

In contrast, while capacitors store electrical energy temporarily; resistors limit the flow of current by providing resistance, and inductors store energy in a magnetic field when electrical current passes through them, they do not actively control current flow in the same way that transistors do.