Is energy produced when a transformer steps up the voltage?
No.
When a transformer steps up the voltage, the voltage increases but the current decreases in the process since the supplied power remains constant.
Now, the power is given by
where V = voltage, I = current.
Since the voltage and current increase and decrease in proportion to each other, the value of power remains constant.
Hence, energy is not produced. Energy = power x time remains constant. (Ans)