Definition of an equivalent circuit: An equivalent circuit is any replacement network that delivers the same terminal voltage and current to a specified load as the original. True or false?

Introduction / Context:
Equivalent circuits (Thevenin, Norton, small-signal models) are used to simplify analysis without changing what the connected load experiences. This concept underpins modular design and black-box testing in electronics.

Given Data / Assumptions:

• The “equivalence” is evaluated at the same two external terminals.
• For any chosen load connected to those terminals, the replacement must yield the same voltage and current as the original.
• Linearity is often assumed for Thevenin/Norton, but equivalence can be defined more broadly if conditions are specified.

Concept / Approach:

If two networks present identical terminal V–I characteristics for the loads of interest, they are equivalent. Thevenin represents the network by Vth in series with Zth; Norton uses In in parallel with Zn. Both produce the same V and I for any load when their parameters satisfy Vth = In * Zth and Zth = Zn.

Step-by-Step Solution:

Verification / Alternative check:

Compute responses to at least two different loads (e.g., open-circuit and short-circuit). If both match and the system is linear, all intermediate loads will match as well, confirming equivalence.

Why Other Options Are Wrong:

• “False” would deny the standard definition used in circuit theory and measurement.

Common Pitfalls:

Forgetting to specify the terminals; equivalence is terminal-specific. Also, for nonlinear circuits, equivalence may hold only over a defined operating region.

Final Answer:

True