계산 방법 Equivalent 저항: Series & Parallel (R₁ + R₂)
Find equivalent 저항 for series (Rₜ = R₁ + R₂) and parallel (1/Rₜ = 1/R₁ + 1/R₂) pairs. 풀이 예제s, traps, and a free calculator.
What Equivalent 저항 Asks
Real circuits often have more than one resistor. Equivalent 저항 Rₜ is a single value that behaves like the whole combination — same total 전류 from the battery or same 전압 drop across the branch.
For two resistors the rules are: series Rₜ = R₁ + R₂, and parallel 1/Rₜ = 1/R₁ + 1/R₂. All values are in ohms (Ω).
If you already have R₁ and R₂, open the free series & parallel 저항 calculator first, then return here for spotting series vs parallel and linking to 옴's law.
Series vs Parallel
Trace the wire: if 전류 must pass through R₁ then R₂ with no split, it is series. If the wire splits so each resistor has its own path between the same two points, it is parallel.
The 공식s
After You Find Rₜ
Use equivalent R in 옴's law V = IR to find total 전류 or 전압 across the combination.
For 전력 dissipation, try the electric 전력 calculator with P = I²R or P = V²/R once you know I or V.
When two resistors divide a supply 전압 (not the same as parallel), use the 전압 divider calculator instead.
단위
풀이 예제
예제 1: series 100 Ω and 220 Ω
Rₜ = 100 + 220 = 320 Ω.
예제 2: parallel 100 Ω and 100 Ω
1/Rₜ = 1/100 + 1/100 = 2/100, so Rₜ = 50 Ω. Shortcut: equal pair → R/2.
예제 3: parallel 6 Ω and 3 Ω
1/Rₜ = 1/6 + 1/3 = 1/6 + 2/6 = 3/6. Rₜ = 2 Ω. 확인: (6×3)/(6+3) = 18/9 = 2 Ω.
예제 4: 12 V across 320 Ω series pair
After 예제 1, I = V/R = 12/320 = 0.0375 A = 37.5 mA total through both resistors.
흔한 실수
확인 It on the 계산기
Series & parallel 저항 calculator.
학습 Rₜ for series and parallel pairs and confirm every circuit home일 number on the calculator.