1. Page 1 Ohm’s Law Engineering Science

2. Page 2 Introduction Ohm’s Law is named after Georg Simon Ohm who was a German Physicist and Mathematician. He discovered an easy way to work out the Voltage, Current and Resistance of a circuit. It is his theory that we still use today.

3. Page 3 The Formula The Formula that is used is V = I x R Using the formula allows you to work out the Voltage of a circuit if you know its Current and Resistance. From this formula we can also swap around the values to find Current (I) and Resistance (R)

4. Page 4 The Triangle To remember all of the calculations, we can use a formula triangle This gives us a way to remember: V = I x R I = V / R R = V / I By covering up parts of the triangle, we are left with the calculation

5. Page 5 Values Things that you need to remember are: Voltage is measured in Volts with the unit V (eg. 25V) Current is measured in Amps with the unit A (eg. 25A) Resistance is measured in Ohms with the unit Ω (eg. 25 Ω )

6. Page 6 Example 1 0.25A 270R What is the Voltage of the circuit?

7. Page 7 Example 2 5000V 270R What is the Current of the circuit?

8. Page 8 Example 3 1.3A 200V What is the Resistance of the circuit?