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→Example Calculations
<math>I\approx8.5A</math>
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====Finding Resistance from Potential Difference and Current====
{| class="wikitable"
| style="height:20px; width: 300px; text-align:center;" |A student measures a [[Potential Difference|potential difference]] of 5.4V and a current of 0.13mA across a component. Calculate the [[Electrical Resistance|resistance]] of the [[Electrical Component|component]].
| style="height:20px; width: 300px; text-align:center;" |Calculating the [[Electrical Resistance|resistance]] of a [[buzzer]] connected in series to a 9V battery with an [[ammeter]] reading of 23mA.
|-
| style="height:20px; width: 300px; text-align:left;" |'''1. State the known quantities'''
V = 5.4V
I = 0.13mA = 0.13x10<sup>-3</sup>
| style="height:20px; width: 300px; text-align:left;" |'''1. State the known quantities'''
V = 9V
I = 23mA = 23x10<sup>-3</sup>
|-
| style="height:20px; width: 300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
<math>I=\frac{V}{R}</math>
<math>0.13 \times 10^{-3}=\frac{5.4}{R}</math>
| style="height:20px; width: 300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
<math>23 \times 10^{-3}=\frac{9}{R}</math>
|-
| style="height:20px; width: 300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
<math>R=\frac{5.4}{0.13 \times 10^{-3}}</math>
<math>R=41538.46\Ohm</math>
<math>R\approx 42000\Ohm</math>
| style="height:20px; width: 300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
<math>R=\frac{9}{23 \times 10^{-3}}</math>
<math>R=391.3043\Ohm</math>
<math>R\approx 390\Ohm</math>
|}