Thread: spark

how are spark producing in a conductor while carrying current?

You don't get sparks in a conductor. They occur when electricity passes through air (or another gas) and ionizes it.

are you asking how a spark gap works??

Originally Posted by sabari raja

how are spark producing in a conductor while carrying current?

Your question is phrased a bit confusingly, so I am not sure what you are asking. So I'll answer the question that you should be asking.

A spark will occur between (not in) two conductors if the electric field is large enough to cause ionization of the insulating material between the conductors. In dry air at sea level, that field is of the order of a few megavolts per meter, if memory serves.

The mechanism is straightforward: If the field is big enough the corresponding electrostatic force can rip electrons free from their host atoms. If, in addition, the mean free path (the average distance between collisions) is large enough, these freed carriers can gain sufficient energy from acceleration by the field to knock additional electrons free when they do collide. The avalanche of charge carriers causes a rapid rise in current. The usual spark is the result of that type of process.

If the field is high enough to cause ionization, but not enough to support avalanching, you can get another kind of phenomenon, known usually as a corona discharge (or just plain corona). You can think of it as a sort of pre-spark without being too far from the truth.