--- title: "Series versus parallel circuit comparison" subject: "Basic Electrical Engineering" chapter: 1 key: "semester_1/basic_electrical_engineering:series-parallel-comparison-table" source: https://www.bctengineer.com/q/semester_1/basic_electrical_engineering/series-parallel-comparison-table site: BCT Engineering --- # Series versus parallel circuit comparison Basic Electrical Engineering · Chapter 1: General Electric System - Asked in: 2074 Asoj, 4 marks - Video: [Series vs Parallel Circuits](https://www.youtube.com/watch?v=O8GgRIIB1Yc) — London Jenks - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_1/basic_electrical_engineering/series-parallel-comparison-table - Whole chapter: https://www.bctengineer.com/md/semester_1/basic_electrical_engineering/chapter-1 ## Question Make comparison table between series and parallel circuit. ## Short answer In series circuits, current is the same, voltage divides, total resistance equals the sum, and an open stops all. In parallel circuits, voltage is the same, current divides, total resistance is the reciprocal sum, and branches operate independently. ## Answer A **series circuit** has components joined end to end so that there is only one path for current. A **parallel circuit** has components joined across the same two nodes so that the current has more than one path. | Point | Series circuit | Parallel circuit | |---|---|---| | Connection | End to end, one path | Across the same two nodes, many paths | | Current | Same through every element | Divides among the branches | | Voltage | Divides among the elements | Same across every branch | | Equivalent resistance | R = R₁ + R₂ + R₃ (larger than the largest) | 1/R = 1/R₁ + 1/R₂ + 1/R₃ (smaller than the smallest) | | Effect of one open element | Whole circuit stops | Other branches keep working | | Voltage division / current division | Voltage divider rule: V₁ = V·R₁/(R₁+R₂) | Current divider rule: I₁ = I·R₂/(R₁+R₂) | | Power in an element | P = I²R, larger for larger R | P = V²/R, larger for smaller R | | Equivalent capacitance | Reciprocal sum (smaller) | Direct sum (larger) | | Use | Fuse, switch with load, string lights | House wiring, appliances | ```text Series: o--[R1]--[R2]--[R3]--o Parallel: +--[R1]--+ o--+--[R2]--+--o +--[R3]--+ ``` ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. Which pair correctly describes current and voltage in a series circuit? A. Current divides; voltage is the same across each element B. Current is the same through each element; voltage divides C. Both are the same everywhere D. Both divide among the elements Answer: B. One path means the same current everywhere, while the supply voltage divides among the elements. (Key point: Current and voltage) 2. Which statement about equivalent resistance is correct? A. Series: smaller than the smallest; parallel: larger than the largest B. Series: sum of resistances; parallel: smaller than the smallest resistor C. Series: reciprocal sum; parallel: direct sum D. Both give a value between the smallest and largest Answer: B. Series R = R1 + R2 + R3 is larger than the largest; parallel 1/R = sum of 1/R is smaller than the smallest. (Key point: Equivalent resistance) 3. If one element opens, what happens in each circuit? A. Series: other loads keep working; parallel: everything stops B. Both keep working C. Series: whole circuit stops; parallel: other branches keep working D. Both stop completely Answer: C. A series circuit has one path so a break stops all current; parallel branches are independent. (Key point: Effect of open element) 4. For capacitors, which rule applies? A. Series: direct sum; parallel: reciprocal sum B. Both use direct sum C. Both use reciprocal sum D. Series: reciprocal sum (smaller); parallel: direct sum (larger) Answer: D. Capacitors combine opposite to resistors: series gives a smaller value, parallel adds directly. 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