What are the two types of variable resistors?

The correct response identifies potentiometers and rheostats as the two types of variable resistors because both components are designed to adjust resistance within a circuit.

A potentiometer is a three-terminal resistor with a sliding or rotating contact that allows for an adjustable voltage divider. It is commonly used for adjusting levels in audio equipment, as well as controlling brightness in lights and other applications requiring varying resistance.

A rheostat, on the other hand, is a two-terminal variable resistor primarily used to control current. It is often found in applications requiring significant power control, such as in light dimmers or motor speed controllers. Rheostats are typically utilized in higher power applications compared to potentiometers.

The other answer choices pertain to different categories of electronic components altogether. Capacitors store electrical energy in an electric field, inductors store energy in a magnetic field, transistors amplify or switch electrical signals, and diodes allow current to flow in one direction only. Transformers and rectifiers serve different purposes related to voltage transformation and conversion of AC to DC, respectively. Thus, the distinction of the correct answer lies in the specific functionality and application of potentiometers and rheostats as variable resistors.