Tangshan Weather China Weather Network

A, because the number of turns is constant, the output voltage of the step-up transformer is constant, so A is wrong;

B, the output voltage of the step-down transformer is the voltage at both ends of the user, so B is wrong;

C, the output power increases, the current on the transmission line increases, and the power loss on the transmission line increases, so c is correct;

D, the ratio of the power lost on the transmission line to the total power =△UU=IRU, where I increases and U remains unchanged, so the ratio increases and D is wrong;

So choose C.