Question

To transfer a fix amount of electrical energy while keeping Ohmic heating low, it is good to increase voltage？

Answer 1

When large amount of electrical energy is to be transfer to long distance then it is better to transfer the electrical energy at large voltage-low current rather than low voltage-high current.The reason is as follows-

We know that when electrical current flows through a conductor then heat is generated and amount of heat generated is given by the equation-

        

where R=resistance of the conductor that carries the electrical energy.so Heat generated in wire is proportional to square of the current.If current is large then heat produce in wire will be also large and a lot of electrical energy will waste due to this heat production.

So to minimize the electrical energy loss due to this heat production it will be good practice to transfer the same amount of power with large voltage and low current.By this method we can transfer same amount of electrical energy with low loss.

For example let we want to transfer P=1000W of electrical energy through the conducting wires whose resistance is 100 ohm.

Let voltage=1000 volt then current I=P/V=1000/1000=1A

then power loss by resistance=I²xR=(1)²x100=100watt

we can transfer the same power with large voltage.Let now voltage V=10000v

then current I=P/V=1000/10000=0.1A

now power loss by resistance=I²xR=(0.1)²x100=1watt

so now power loss due to heat is reduced to 100 times.

Let we