What causes electrons in an electric current to flow slowly in that circuit?

Answer 1

We don't normally think of electrons "flowing slowly" in a circuit. In general, electricity operates at the speed of light. It is circuit characteristics like conductivity and resistance that determine how much current will flow in a circuit when a given voltage is applied. We will discover that more conductivity will permit more current, and more resistance will limit current (for the same applied voltage).

It is possible that inductance and capacitance could be looked at as circuit characteristics that cause current to "flow slowly" in that there is a time difference between when voltage and current appear in a circuit. But we usually think of electricity as a phenomenon that works at the speed of light.

The answer that has been posted might confuse someone beginning an investigation of the way electricity works. But it is suggested that the basic models of electricity be considered and even reviewed to get a handle on the concept of electron flow. One idea that may be offered in closing is that when two ends (wires) of an electric circuit are connected to a voltage source, current will begin to flow. And when one electron "goes into" one end of the wire, one will "come out" of the other end. It is not the same electron. The electrons available to support current flow in the circuit will "shift over one place" to accommodate the current flow.

Alternative Answer

Electrons move within a conductor in a rapid, chaotic, haphazard, way. When a potential difference is applied across a conductor, the electrons continue to move in this chaotic way; however there is a drift towards one end of the conductor. So, electron 'flow' is very, v-e-r-y, slow (an electron moving within a flashlight bulb's filament is unlikely to move throughout the length of that filament within the lifetime of the battery!), although the effect is more-or-less instantaneous along the length of the conductor.