phys: clarify interal resistance

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eggy 2021-02-03 08:59:35 -05:00
parent 8922878396
commit 1e03ec4e7b

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@ -983,7 +983,7 @@ $$\sigma=\frac{1}{\rho}$$
**Electromotive force** (emf, $\epsilon$) is not a force but is the voltage gained when charges pass through a cell, representing the total electric potential energy provided to the whole circuit. **Electromotive force** (emf, $\epsilon$) is not a force but is the voltage gained when charges pass through a cell, representing the total electric potential energy provided to the whole circuit.
All cells have **internal resistance**, which is the resistance of th cell itself. Where $P$ is the power dissipated in the cell, $I$ is the current the cell produces, and the internal resistance of the cell $r$: All cells have **internal resistance**, which is the resistance of th cell itself. It is depicted as the resistance being in series with the electromotive force. Where $P$ is the power dissipated in the cell, $I$ is the current the cell produces, and the internal resistance of the cell $r$:
$$P=I^2r$$ $$P=I^2r$$
The voltage across the terminals of a battery is equal to, where $I_r$ is the current across the internal resistance: The voltage across the terminals of a battery is equal to, where $I_r$ is the current across the internal resistance: