Series circuit voltage law (KVL application): Which statement correctly describes the total voltage in a series circuit with several elements?
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AThe total voltage is equal to the sum of the individual voltages in a series circuit.
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BThe total voltage equals the average value of the individual voltages.
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CThe total voltage is equal to the total current divided by the total resistance.
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DThe total voltage in a series circuit is always less than the smallest individual voltage.
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ENone of the above
Answer
Correct Answer: The total voltage is equal to the sum of the individual voltages in a series circuit.
Explanation
Introduction / Context:Kirchhoff’s Voltage Law (KVL) states that the algebraic sum of all voltages around any closed loop is zero. In a series circuit driven by a source, this implies the source voltage equals the sum of the voltage drops across each series element. This rule underpins practical measurements and design checks in power supplies and analog signal chains.
Given Data / Assumptions:
- Series connection (single loop) of multiple components.
- Ideal wiring (negligible wire resistance).
- Steady-state conditions.
Concept / Approach:KVL: ΣV = 0 around a loop. If the source provides V_s and the drops are V_1, V_2, …, V_n, then V_s − (V_1 + … + V_n) = 0 → V_s = V_1 + … + V_n. This is a direct and general result independent of the types of series components (R, L, C, or semiconductors in steady state).
Step-by-Step Solution:Identify all series elements and measure individual drops.Apply KVL across the loop.Sum the individual voltages and equate to source.Confirm arithmetic: the sum must match the source within measurement error.
Verification / Alternative check:Use a DMM to measure each drop and the source; summing the measured drops should reproduce the source voltage—an effective diagnostic for wiring or component faults.
Why Other Options Are Wrong:(b) “Average” is not a circuit law. (c) V = I*R_total applies only if all elements are resistive; still, the correct statement is about the sum of drops. (d) The total cannot be smaller than each individual drop in a series sum.
Common Pitfalls:Forgetting to account for device polarities; misreading AC RMS versus peak quantities when summing.
Final Answer:The total voltage is equal to the sum of the individual voltages in a series circuit.