Linear circuit
A linear circuit is an electronic circuit which obeys the superposition principle. This means that the output of the circuit F(x) when a linear combination of signals ax1(t) + bx2(t) is applied to it is equal to the linear combination of the outputs due to the signals x1(t) and x2(t) applied separately: F ( a x 1 + b x 2 ) = a F ( x 1 ) + b F ( x 2 ) {\displaystyle F(ax_{1}+bx_{2})=aF(x_{1})+bF(x_{2})\,} It is called a linear circuit because the output voltage and current of such a circuit are linear functions of its input voltage and current.