| (3.5) |
|
units: ohms . m |
| The power density based on Ohm's law is | ||
| (3.6) |
|
units: ohms . m |
| where Ac = cross-sectional area of the rod (m2) and is given in (3.5). | ||
| Substituting from (3.5) and (3.6) into (3.1), we get the differential equation | ||
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||
| which can be simplified to | ||
| (3.7) |
|
|
| where | ||
| (3.8) |
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|
| (3.9) |
|
to obtain the temperature distribution in the rod.