Question:

Step-Up Transformer ?

(1) A Step Up transformer steps up voltage.(2) Voltage is directly proportional to Power.Conclusion: A Step Up transformer has the capacity to increase Power.Contradiction: By First Law of Thermodynamics, Energy can neither be created nor be destroyed. Hence No one can create energy out of thin air like, that of by just using a Step Up transformer to increase voltage and hence power.Where is the whole theory wrong?

Answer:

voltage is inversely proportional to current, if the voltage increases then the current decreases . as long as the power remains the same. P I x V if you increase the voltage then the current should decrease proportionaly, that is how they can distribute high voltage over long distances using such small conductors . the current is very low
P I*V A step up transformer DOES increase output voltage BUT it also lowers output current. So it's incorrect to say that Voltage is directly proportional to Power. Voltage is Power divided by the Current. If the output voltage doubles, output current drops by a factor of 2. This way, total output power stays the same as input power, and all laws of Thermodynamics are satisfied. P_in I_in * V_in I_out * V_out P_out

Share to: