Question

In HVDC transmission why current decreases with increase in voltage. Please explain me in Quantum mechanics.

Answer 1

Simply Ohms law! No QM needed.

Answer 2

The Idea is to transfer as much power across those lines as possible with little loss of power in the form of an "IR" drop that is a drop in voltage from the power station to the point of use. The larger the current the more voltage drop you will have and the greater will be the power loss to the heating of the transmission wire. The way to do this is to boost the voltage and reduce the current. So for example to transfer 100Kw of power you could boost the voltage to 100KV with a current of 1amp or leave it at 100V and have a current of 1000A. If you did the latter you would need transmission lines would be about an inch and a half thick. The lines would be very expensive and weight pounds per foot.

With the 100KV @ 1amp the wire need be only a millimeter or so thick. The number aren't exact but you get the picture.

Answer 3

@gleem Theoretically I has a clear idea of ohms law works. But I want to understand it in more basic level.
Like if current got reduced, to my understanding it means that the speed with which the electrons moving got reduced. as I=Q/t. I am confused in this area. Please give me explanation in this passion.
Elaborate the behaviour of electrons.

Answer 4

Current is the flow of electron under the influence of a potential difference ie voltage.

The speed of the electrons in a conductor is very slow and is referred to as the Drift velocity. The number of electrons moving in a wire is enormous think 10^22 electrons per cc. The electrons are packed throughout the conductor an move as a group through the conductor. An individual electron may take hours to move through a conductor.