# How fast does current flow? And the magnetic field? [closed]

A conductor carries 10 Amps, and generates a magnetic field $B$.

1. How fast does it take for that current to flow from the wire throughout the entire circuit?

2. And how fast does it take for the magnetic field to be created?

## closed as unclear what you're asking by Alfred Centauri, Brandon Enright, Kyle Kanos, Emilio Pisanty, Waffle's Crazy PeanutMar 27 '14 at 12:44

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• Take a look at drift velocity for your first question. – BMS Mar 26 '14 at 1:46
• @BMS I'm a bit confused can you explain it in a answer? How fast current flows and drift velocity? – Pupil Mar 26 '14 at 2:29
• Electromagnetic perturbation flows close to speed of light and this is speed of current despite drift velocity of electrons are low. – Schrödinger's Cat Mar 26 '14 at 3:11
• @SachinShekhar Two know that my electronic's current moves near the speed of light and any conducting wire transfers current at that speed is phenomenal. – Pupil Mar 26 '14 at 4:26
• Related: physics.stackexchange.com/q/335/2451 , physics.stackexchange.com/q/17741/2451 and links therein. – Qmechanic Mar 26 '14 at 19:01

However, as soon as an electron starts to move, it affects other electrons around it. Because of this, the current flows out of the other end of the cable almost immediately. As a result, electricity travels down the wire at about $2/3$ of the speed of light.
Magnetic fields, on the other hand, travel through space at the same speed as electric fields: the speed of light. I don't know how fast they travel through magnetic materials, but it will be somewhat slower than $c$.