Electric Currents & Ohm’s Law – Charge Velocity and Velocity of Field Propagation

The speed with which charge drifts in a conductor is called the velocity of charge. As seen from above, its value is quite low, typically fraction of a metre per second. However, the speed with which the effect of e.m.f. is experienced at all parts of the conductor resulting in the flow of current is called the velocity of propagation of electrical field. It is independent of current and voltage and has high but constant value of nearly 3 × 10⁸ m/s.