Number 4 –> What is an equivalent circuit and how is it used?

When analyzing electrical circuits — including those for ac induction motors and dc motors — if the circuit contains two or more of the same passive elements (such as resistors) and is wired exclusively in series or exclusively in parallel, the circuit can be drawn with a simpler representation that contains the voltage source and a single, equivalent passive element. This simplified version retains the electrical characteristics of the original circuit and is referred to as an equivalent circuit.

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