Applicability of superposition: The superposition theorem is primarily useful for single-source circuits. True or false?
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ATrue
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BFalse
Answer
Correct Answer: False
Explanation
Introduction / Context:The superposition theorem is a linear-circuit tool used to analyze the combined effect of multiple independent sources by summing individual contributions. Understanding when it helps is essential for efficient problem solving.
Given Data / Assumptions:
- We consider linear circuits (R, L, C, linear dependent sources).
- Superposition applies to voltages and currents but not directly to powers (since power is nonlinear in V and I).
- Independent sources may be voltage or current sources at different locations or frequencies.
Concept / Approach:
Superposition shines in multi-source circuits: deactivate all but one independent source at a time (voltage sources → short; current sources → open), compute the response, then sum all contributions. In a single-source circuit, superposition offers no advantage; there is only one contribution to compute, so the theorem is trivially satisfied but not particularly useful.
Step-by-Step Solution:
Identify all independent sources.Analyze the circuit with only one active source at a time.Sum all individual responses to obtain the total response.Avoid applying superposition to powers; compute power from the final V and I.Verification / Alternative check:
Compare with nodal or mesh analysis. For many sources, superposition can simplify algebra by reusing partial solutions, confirming its utility specifically in multi-source scenarios.
Why Other Options Are Wrong:
- “True” incorrectly suggests superposition is best for single-source circuits, where it is unnecessary.
Common Pitfalls:
Incorrectly “turning off” dependent sources. Dependent sources remain active because their values depend on circuit variables. Also, attempting to superimpose power directly leads to errors.
Final Answer:
False