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Formula: **Equivalent resistance of a series connection of resistors**

$$R ~=~ R_1 ~+~ R_2 ~+~ R_3 ~+~ ...$$
$$R ~=~ R_1 ~+~ R_2 ~+~ R_3 ~+~ ...$$

## Equivalent resistance

`$$ R $$`Unit

`$$ \mathrm{\Omega} $$`

The total resistance (equivalent resistance) of a series circuit is the sum of individual resistors. For example, if you have a series circuit with three resistances \(R_1\), \(R_2\) and \(R_3\), then the total resistance \(R\) is given by:

`\[ R ~=~ R_1 ~+~ R_2 ~+~ R_3 \]`For example, if the first resistance is \(R_1 = 200 \, \Omega \), the second resistance is \(R_2 = 50 \, \Omega \), and the third resistance is \(R_3 = 100 \, \Omega \), then the total resistance of the series circuit is:
`
\begin{align}
R &~=~ 200 \, \Omega ~+~ 50 \, \Omega ~+~ 100 \, \Omega \\\\
&~=~ 350 \, \Omega
\end{align}
`

## Single resistance

`$$ R_1 $$`Unit

`$$ \mathrm{\Omega} $$`

One of the resistances of the series circuit.