As an expert in the field of electrical engineering, I can provide you with a detailed explanation of how fast electricity travels through a wire.

Electricity is a form of energy that can be transferred through a wire by the movement of electrons. However, it's important to clarify that the speed at which electricity travels through a wire is not the same as the speed at which electrons move.

The speed of electricity in a wire is actually determined by the speed at which the electric field propagates through the wire. When a voltage is applied across the ends of a wire, it creates an electric field that extends along the wire. This electric field then causes electrons to move, but the speed at which the electric field propagates is much faster than the speed of the electrons themselves.

The speed of the electric field in a wire is approximately the speed of light, which is about 186,282 miles per second (299,792 kilometers per second) in a vacuum. However, in a wire, this speed is slightly reduced due to the properties of the material and the resistance it offers to the flow of electrons. Nevertheless, the propagation speed of the electric field is still extremely fast and is typically in the range of 70% to 90% of the speed of light.

It's important to note that the actual movement of electrons through the wire is quite slow. Electrons move through the wire at a drift velocity, which can be as slow as a few millimeters per second. This is much slower than the speed at which the electric field propagates. The reason for this discrepancy is that only a small fraction of the electrons in the wire are actually moving at any given time. The majority of electrons are stationary or moving at a very slow pace.

Despite the slow movement of electrons, the overall effect of the electric field and the subsequent movement of electrons results in the almost instantaneous transfer of electrical energy along the wire. This is why when you flip a switch to turn on a light, the light bulb responds almost immediately, even if the wire is several kilometers long.

In summary, while electrons move slowly through a wire, the speed at which electricity travels is determined by the speed of the electric field, which is close to the speed of light. This allows for the rapid transfer of electrical energy and the near-instantaneous response of electrical devices when a voltage is applied.

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Light travels through empty space at 186,000 miles per second. The electricity which flows through the wires in your homes and appliances travels much slower: only about 1/100 th the speed of light.read more >>