Ohm’s Law, Grade 10 Physics 1/ Ohm’s Law The voltage is the change in potential energy or work done when charge moves between two points in the circuit. The greater the resistance to charge moving the more work that needs to be done. The work done or voltage thus depends on the resistance. The potential difference is proportional to the resistance. Definition: Ohm’s Law Voltage across a circuit component is proportional to the resistance of the component. Use the fact that voltage is proportional to resistance to calculate what proportion of the total voltage of a circuit will be found across each circuit element. We know that the total voltage is equal to V1 in the first circuit, to V1 + V2 in the second circuit and V1 + V2 + V3 in the third circuit. We know that the potential energy lost across a resistor is proportional to the resistance of the component. The total potential difference is shared evenly across the total resistance of the circuit. This means that the potential difference per unit of resistance is Then the voltage across a resistor is just the resistance times the potential difference per unit of resistance Xem thêm: Physics 10.IX Electric Circuits High School Students Studying the Sciences Physics