1. What is a typical drift speed of electrons that make up a current in a typical DC circuit?
(zero, less than 1 cm/s, about 10 m/s, or the speed of light)
2. What is the typical drift speed in a typical AC circuit? (zero, less than 1 cm/s, about 10 m/s, or the speed of light)
1. less than 1 cm/s. The exact number depends upon current and wire diameter
2. On the average, zero. Electrons go back and forth in AC circuits. Maximum values are comparable to DC, but plus and minus
To determine the answers to these questions, let's start by understanding what drift speed is. In a circuit, electric current is the flow of electrons. The drift speed refers to the average speed at which electrons move through the circuit.
1. In a typical DC circuit, the drift speed of electrons is relatively slow. It is typically less than 1 cm/s. While individual electrons can move quite fast, colliding with other atoms and electrons in the process slows down their average drift speed. Therefore, the correct answer is "less than 1 cm/s."
2. In a typical AC circuit, the direction of the current periodically changes, alternating between positive and negative. As a result, the electrons experience a back-and-forth motion rather than a unidirectional flow. Consequently, their average drift speed is even slower compared to a DC circuit. In an AC circuit, the typical drift speed of electrons is significantly less than 1 cm/s. Thus, the correct answer is again "less than 1 cm/s."