An example of an **active element** in electronics is a **transistor**.
Active elements are components that can provide power gain or control the flow of electrical signals. A transistor, for example, can amplify weak electrical signals, making it a key component in circuits like amplifiers, oscillators, and switches.
Other examples of active elements include:
- **Operational amplifiers (op-amps)**: These can amplify voltage signals in a variety of applications.
- **Diodes** (in some configurations, like light-emitting diodes or LEDs): While diodes are typically considered passive, they can act as active elements when used in certain contexts.
The main feature of active elements is that they require an external power source to operate and can increase the signal's power or provide energy to the circuit.