Electrical Calculator: Ohm's & Joule's Laws

Enter ANY TWO values greater than zero
leaving the other two values zero or empty:

Voltage Current Resistance Power
Volts Amperes Ohms Watts
V I R P
Two COMPUTED values:
Voltage Current Resistance Power
Volts Amperes Ohms Watts
V I R P

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 (18181889) 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.

Website by Jim Shook 04/03/2007
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