This is a picture of George Ohm. He was a young man when he learned about Volta inventing the battery and he became interested in electrical circuits. He studied the relationships between the voltage and resistance in a circuit. The unit of resistance is called Ohm in his honor. Its symbol is the great letter omega, which looks like an upside down horse shoe. Ω
George Simon Ohm (1789-1845), British physicist.. IRC. 2005. Discovery Education. 22 June 2009 <http://streaming.discoveryeducation.com/>
This is Andre-Marie Ampere who studied electrical circuits in France and developed a method of measuring current. The unit for current, the Ampere is named after him. Its symbol is a capitol A.
The relationship between voltage, current and resistance is called Ohm’s Law. The equation is simple, but it has great value in building and maintaining electrical circuits. Electrical potential, or voltage is equal to the current in amperes times the resistance in ohms.
V = I x R
Since V = I x R, then I = V/R and R = V/I.
These relationships can be drawn another way to help you remember:
By using the circle, you can cover the unknown quantity and the other two will appear in the correct relationship to solve for the unknown. For example if you cover I then V will appear over R.