12 Formulas used:

V = I * R         V = P / I         V = (P * R)1/2

I = V / R         I = P / V         I = (P / R)1/2

R = V / I          R = P / I2        R = V2 / P

P = I * V          P = R * I2        P = V2 / R


Brief History of Ohm's Law

Georg Simon Ohm (1789-1854) was a German physicist born in
Erlangen, Bavaria. As a high school teacher, Ohm started his
research with the recently invented electrochemical cell,
invented by Italian Count Alessandro Volta. Using equipment of
his own creation, Ohm determined that the current that flows
through a wire is proportional to its cross sectional area and
inversely proportional to its length.

Using the results of his experiments, Georg Ohm was able to 
define the fundamental relationship among voltage, current,
and resistance.  This became Ohm's Law and represents the true
beginning of electrical circuit analysis.

Brief History of Joule's Law

James Prescott Joule (1818–1889) was an English physicist, born
in Sale, Cheshire. Joule studied the nature of heat, and
discovered its relationship to mechanical work. This led to the
theory of conservation of energy, which led to the development
of the first law of thermodynamics. The SI unit of work, the
joule, is named after him. He worked with Lord Kelvin to
develop the absolute scale of temperature, made observations on
magnetostriction, and found the relationship between the flow
of current through a resistance and the heat dissipated, now
called Joule's law.