19th Century Pioneer

Georg Simon Ohm (1789 – 1854).  Germany.

A German physics professor that discovered the relationship between voltage, current and resistance.  His work resulted in the formula E = I x R, known as ohms law. The unit of electrical resistance – the Ohm was named in his honor.

E (electromotive force) represents the voltage, V. 
I stands for electrical current.
R stands for resistance.

If the current (I) and resistance ( R ) of a circuit are known, then find the voltage (E) by multiplying the current by the resistance.           E = I x R

If the voltage (E) and resistance (R) of a circuit are known, then find the current (I) by dividing Voltage (E) by resistance ( R ).               I = E / R

If the voltage (E) and current ( R ) of a circuit are known, then find the resistance ( R ) by dividing voltage (E) by current ( I).                                 R = E / I

If the voltage (E) and current (I) of a circuit are known, then find the Power consumed in the circuit by multiplying current (I) by voltage ( E ).        P = I x E

Other relationship formulas:

I = P / E                I ² = P / R  

E = P / I                E ² = P x R

R = E ² / P            R = P / I ²

P = I ²/ R              P = E ²/ R