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- PHY102 Physics II © Dr.Cem Özdoğan
- 28-5 Crossed Fields: The Hall Effect
- When a conducting strip carrying a current i is placed in a uniform magnetic field, some charge carriers (with charge e) build up on one side of the conductor, creating a potential difference V across the strip.
- The polarities of the sides indicate the sign of the charge carriers.
- A Hall potential difference V is associated with the electric field across strip width d, and the magnitude of that potential difference is V =Ed.
- When the electric and magnetic forces are in balance (Fig. 28-8b),
- where vd is the drift speed.
- Where J is the current density, A the cross-sectional area, e the electronic charge, and n the number of charges per unit volume.
- Here, l=( A/d), the thickness of the strip.
- Fig. 28-8 A strip of copper carrying a current i is immersed in a magnetic field . (a)The situation immediately after the magnetic field is turned on. The curved path that will then be taken by an electron is shown. (b) The situation at equilibrium.
- The number density of the charge carriers
Fig. 28-8 (c) For the same current direction, if the charge carriers were positively charged, they would pile up on the right side, and the right side would be at the higher potential.