# Linear Circuit
**A circuit whose output voltage and current are linear functions of its input voltage and current.**
A **linear circuit** is a circuit which has a *linear relationship* between its output and input voltage and current. A circuit is also linear if it follows the [[superposition]] principle.
Linear circuits consist of components whose values *do not* change depending on the voltages and current in the circuit. This property is known as being *linear time-invariant*.
Examples of *linear components* are
- Ideal resistors, [[Capacitor|capacitors]], [[Inductor|inductors]]
- Ideal non-saturated operational amplifiers
- Amplifiers
- Differentiators
- Integrators
- Linear electronic filters