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Kirchoff’s Voltage Law

Mahi Tuatahi 🔗

Calculate the voltage used by each resistor.
Strategy: Start by calculating the total resistance and the total current.

Kirchoff’s Laws: Voltage 🔗

The sum of the potential differences (voltages) in any closed loop is zero.
OR: That is to say, over a loop, the full voltage (energy) of the power supply must be consumed.

$$ \begin{aligned} V_{1} + V_{2} + V_{3} &= 0 \newline V_{1} + V_{4} &= 0 \end{aligned} $$

Series CircuitParallel Circuit
Current (I) in Amperes, $A$Same through all componentsAdds up to the supply
Voltage (V), in Volts, $V$Adds up to the supplySame across all equi-resistant paths
Resistance (R) in Ohms, $\Omega$Combine to give more resistance ($R_{T}=R_{1}+R_{2}+…$)Combine to give less resistance ($\frac{1}{R_{T}}=\frac{1}{R_{1}}+\frac{1}{R_{2}}+…$)

Pātai: Harder 🔗

Calculate all unknown values.
Strategy: You should start by calculating the total resistance and total current. Then, calculate the voltage used by the resistor in series with the power supply.

Practice 🔗

Homework: A5, B2 due Monday!

Confirming Kirchoff’s Voltage Law 🔗