Question

aplicable of superpostion theorem

Answer 1

The superposition theorem applies only when all the components of the circuit are linear, which is the case for resistors, capacitors and inductors. An example that allows me to understand the non applicability of this principle is the following: Imagine you have an NPN BJTransistor with circuits providing current to the base (enough to put the transistor ON) and voltage to the collector, the emitter is connected to an impedance. The transistor is ON and is draining current from C to E. Applying the superpistion principle will short circuit the current source, wich means the transitor turns OFF: No current at E. Then, we put back the current source and ground the voltage source at C: no significant current at E. The sum of the currents at E obtained by applying the superposition principle E will be very negligible comparing to it’s actual counterpart. The particularity of non-linear systems is that their output is non linear to their input (obviously). For more info about linearity of systems, report to a signal processing course about LTIs (Linear Time Invariant systems).