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Joule immersed a length of wire in a fixed mass of water and measured the temperature rise due to a known current flowing through the wire for a 30 minute period. By varying the current and the length of the wire he deduced that the heat produced was proportional to the square of the current multiplied by the electrical resistance of the ...
Between 1840 and 1843, Joule carefully studied the heat produced by an electric current. From this study, he developed Joule's laws of heating, the first of which is commonly referred to as the Joule effect. Joule's first law expresses the relationship between heat generated in a conductor and current flow, resistance, and time. [1]
The ratio between the emf and temperature difference is the Seebeck coefficient. A thermocouple measures the difference in potential across a hot and cold end for two dissimilar materials. This potential difference is proportional to the temperature difference between the hot and cold ends.
A heat current or thermal current is a kinetic exchange rate between molecules, relative to the material in which the kinesis occurs. It is defined as the net rate of flow of heat . The SI unit of heat current is the watt , which is the flow of heat across a surface at the rate of one Joule per second.
In the table below are Seebeck coefficients at room temperature for some common, nonexotic materials, measured relative to platinum. [8] The Seebeck coefficient of platinum itself is approximately −5 μV/K at room temperature, [9] and so the values listed below should be compensated accordingly. For example, the Seebeck coefficients of Cu, Ag ...
The relationship between thermal conductance and resistance is analogous to that between electrical conductance and resistance in the domain of electronics. Thermal insulance (R-value) is a measure of a material's resistance to the heat current. It quantifies how effectively a material can resist the transfer of heat through conduction ...
The Boltzmann constant sets up a relationship between wavelength and temperature (dividing hc/k by a wavelength gives a temperature) with one micrometer being related to 14 387.777 K, and also a relationship between voltage and temperature (kT in units of eV corresponds to a voltage) with one volt being related to 11 604.518 K.
The relationship shows that is the value of the partial differential of reactivity with respect to temperature and is referred to as the "temperature coefficient of reactivity". As a result, the temperature feedback provided by α T {\displaystyle \alpha _{T}} has an intuitive application to passive nuclear safety .