text: The inverse of the Villari effect, in which magnetization causes a ferromagnetic material to change in length, is called this scientist's magnetostriction.
full_question: The inverse of the Villari effect, in which magnetization causes a ferromagnetic material to change in length, is called this scientist's magnetostriction. This physicist is the first namesake of a coefficient that is anomalously negative for hydrogen gas at room temperature, equal to the derivative of pressure with respect to temperature at constant enthalpy, and symbolized mu. His "first law" gives the heat radiated from a resistor as proportional to the current squared. This scientist attached a falling weight to a series of (*) spinning plates suspended in water, heating up the water, in an experiment that proved conservation of energy. His namesake unit equals a volt times a Coulomb, or a Watt times a second. For 10 points, name this Englishman whose SI unit measures energy.
first_sentence: The inverse of the Villari effect, in which magnetization causes a ferromagnetic material to change in length, is called this scientist's magnetostriction.
raw_answer: James Prescott Joule 