A closed loop that allows electrical current to flow.

A circuit with a break in the closed loop, preventing current flow.

The sum of all voltage drops and rises around any closed loop in a circuit must equal zero.

The total current entering a junction must equal the total current leaving the junction.

A material's property that describes how much it resists the flow of current, represented by ρ.

The total energy a battery can provide to a charge; the voltage when no current is drawn.

Sum the individual resistances: $R_s = R_1 + R_2 + R_3 + ...$

Use the reciprocal formula: $\frac{1}{R_p} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + ...$

Use the equation: $V_{terminal} = ε - Ir$, where ε is the EMF, I is the current, and r is the internal resistance.

A closed loop that allows electrical current to flow.

A circuit with a break in the closed loop, preventing current flow.

The total energy a battery can provide per unit charge; the voltage when no current is drawn.

A material's property that describes how much it resists the flow of current.

The actual voltage provided by a battery when current is flowing, which is less than the EMF due to internal resistance.

The resistance within a real battery that affects its terminal voltage.