Tellegen’s theorem (as applicable to any lumped d.c. network, regardless of the elements being linear or non-linear, time-varying or time-invariant) implies that
1
sum of the voltage drops across each network element is equal to the total voltage applied to the network
2
sum of the powers taken by all elements, in the network, within the constraints imposed by KCL and KVL is zero
3
sum of the currents meeting at any node is not the same as the current in that mesh
4
it is applicable to a branch which is not coupled to other branches of the network