let's consider this situation in which the two ports of a transmission line are connected to a short circuit and to an inductor:
The transmission line is supposed to be lossless. My book makes a mathematical analysis in order to find the resonance frequency (precisely, resonance frequencies) of this network, which may start to oscillate.
But my question is: how can it start to oscillate on its own (since it is a passive device)? I have understood that there are no losses, but I think it is necessarily a form of excitement or accumulated energy in the circuit (for example, to make an LC circuit oscillate, the capacity must be pre-charged at the time of closing the switch).
Oscillation means voltage + current and so energy. And it cannot create energy from 0.