when a electric potential difference is applied across the metallic wire ,the loosely attached free electrons start moving towards the positive terminal to the cell .this continuous flow of electrons constitutes the electric current.but it also means that at a time when all the electrons get aligned there will be no flow of electricity in the circuit.plz explain?
-
Electrons also flow from the negative terminal to replace those that moved to the positive terminal. There is a constant flow of electrons from the negative terminal, through the metal, back to the positive terminal and through the cell.
This is why we call this a "complete circuit". The current flows in a complete circuit - like a performer on the night club "circuit". They are going from place to place, sorta' round and round.
The cell provides the force to push (and pull) the electrons around the circuit. The cell provides what we call EMF (ElectroMotive Force). It is a force that pushes and pulls electrons.
The cell is constantly trying to pull electrons into its positive terminal and push them out its negative terminal.
We also call EMF "Voltage" and the amount of force is measured in "Volts" - more volts - more force.
Think of a water pump with the output pushing water through a hose that connects back to the pump input. The same water flows round and round. It does not build up in one place.
This is why we call this a "complete circuit". The current flows in a complete circuit - like a performer on the night club "circuit". They are going from place to place, sorta' round and round.
The cell provides the force to push (and pull) the electrons around the circuit. The cell provides what we call EMF (ElectroMotive Force). It is a force that pushes and pulls electrons.
The cell is constantly trying to pull electrons into its positive terminal and push them out its negative terminal.
We also call EMF "Voltage" and the amount of force is measured in "Volts" - more volts - more force.
Think of a water pump with the output pushing water through a hose that connects back to the pump input. The same water flows round and round. It does not build up in one place.
-
The situation is correct, except that current will continue to flow as long as the wire is connected to both terminals of the battery. The electrons will flow from the negative terminal of the battery to the positive terminal and will continue until the wire is disconnected or the battery goes dead. Once the wire is disconnected, even if one end is still connected, the current flow stops. If just the negative terminal is connected a few electrons will flow into the wire then everything stops. If only the positive terminal is connected, any excess electrons will be drawn to the battery, then the flow stops. But if both ends of the wire are connected to the battery, the current flow will continue. As a result of this flow, a magnetic field will be set up around the wire - this can be detected with a compass. Also due to resistance on the wire, it's temperature will increase. (It may get very hot depending on the amount of current!)