8. A magnetic field can be used to determine the sign of charge carriers in a current-carrying wire. Consider a wide conducting strip in a magnetic field oriented

as shown in ▼ Figure 19.29. The charge carriers are deflected by the magnetic force and accumulate on one side of the strip, giving rise to a measurable voltage across it. (This is known as the Hall effect and the voltage is the Hall voltage.) If the sign of the charge carriers is unknown (they are either positive charges moving as indicated by the arrows in the figure or negative charges moving in the opposite direction), discuss how the polarity of the Hall voltage allows the sign of the charge to be determined. Assume that only one type of charge carrier is responsible for the current and consider each case.

Transcribed Image Text:

B (a) (b) v