Series Resistance

Formula

Description

Resistors connected in series carry the same current, and their resistances add directly to give the total resistance. The total is always greater than any individual resistor in the chain. This is because each resistor adds its own voltage drop, and by Kirchhoff's Voltage Law the sum of all drops equals the source voltage. Series resistance is commonly used for voltage dropping, current limiting, and creating precise resistance values not available as single standard components.

Variables

• Rtotal — Total equivalent resistance (Ω)
• R1, R2, ... Rn — Individual resistor values (Ω)

Practical Notes

Series connections are also used for voltage sensing (current shunt resistors) and for distributing power dissipation across multiple components when a single resistor's wattage rating is insufficient.