Electric current flows through a long rod generating thermal energy at a uniform volumetric rate of

I don't know if you need to complete this question or do it otherwise, however, I managed to find on the Internet on several places this completion of your sentence:

Electric current flows through a long rod generating thermal energy at a uniform volumetric rate of q = 2 x 10 ⁶ W/m³.

I'm not sure whether that is the answer you were looking for, but that's what I found.