# Resistance in series and parallel Circuit

### Resistance in Series and Parallel Circuit

1. In a series circuit, the effective resistance is equal to the sum of the individual resistance, as shown in the following equation.
$R= R 1 + R 2 + R 3$
2. In a parallel circuit, the effective resistance of the resistors can be calculated fro the following equation.
$R= ( 1 R 1 + 1 R 2 + 1 R 3 ) −1$

Example:

Find the equivalent resistance of the connection shown in the diagram above
$R=2+3+6=11Ω$ (b)
$R= ( 1 3 + 1 3 + 1 3 ) −1 =1Ω or R=3Ω÷3=1Ω$ (c)
$R= ( 1 6 + 1 6 ) −1 =3Ω R=6Ω÷2=3Ω$ (d)
$R=3+ ( 1 2 + 1 2 ) −1 =4Ω$