1. The problem statement, all variables and given/known data If you step up the voltage in a wire by a factor of 100, how is heat affected? A. No change B. Heat loss increases by a factor of 10000 C. Heat loss decreases by a factor of 10000 D. Not enough information to tell Answer: "C, heat loss decreases by a factor of 10000 because the joule heat generated is I2 * R and since P=IV, a 100fold increase in V is a 100fold decrease in I." Another short question, please: Regarding the V in P=IV. Does V correspond to the voltage drop of the circuit element (resistor, light bulb, etc) or the voltage of the emf source? 2. Relevant equations P=IV, V=IR 3. The attempt at a solution My most recent attempt was to use P=V^2/R so we can only focus on V and P. BUT, this tells me that power increases, not decreases. Is the book wrong?