Answer:
In applying the superposition theorem:
D. the sources are considered one at a time with all others replaced by their internal impedance.
Step-by-step explanation:
Superposition Theorem:
According to this theorem, in a linear electrical circuit with more than one power sources, the current or voltage in any branch of circuit is equal to the sum of currents or voltages produced by the each power source independently while other are replaced by their internal impedance.
- According to this theorem, we replace all the voltage sources by short circuit while current sources are replaced by the open circuit.
- This theorem is applicable for linear circuitry and only for current and voltage.