PHY 2323 Lecture Notes - Lecture 9: Electron Mobility, Ampere

• School: University of Ottawa
• Department: Physics
• Course: PHY 2323
• Professor: Michel Godin

Document Summary

In electrostatic equilibrium, e = 0 inside a conductor. However, when we apply a potential difference (voltage) at both ends of a conductor, we deposit equal but opposite amounts of charge on either end of the conductor. This e-field induces movement of charges (current) A current of 1 ampere corresponds to the transportation of one coulomb of charge in one second. In a typical conductor, electrons are moving at about (cid:883)(cid:882)6(cid:1865)/(cid:1871) (1,000,000 m/s) They experience about (cid:883)(cid:882)14 collisions per second. Their average velocity (drift velocity) is quite slow. But they collide with something about 100,000,000,000,000 times/sec. Positive current flows in the same direction as the electric field. Note: electrons are actually moving in the opposite direction to current, by convention. Electro(cid:374)"s average loss of (cid:373)o(cid:373)e(cid:374)tu(cid:373) per collisio(cid:374): (cid:1865)(cid:1874) Average rate at which electrons lose momentum: Rate at which electron gains momentum due to (cid:1831): (cid:1857)(cid:1831) (cid:1865)(cid:1874) = (cid:1857)(cid:1831) (cid:4666):(cid:1857)(cid:1864)(cid:1857)(cid:1855)(cid:1872)(cid:1870)(cid:1867)(cid:1866)(cid:1865)(cid:1867)(cid:1854)(cid:1864)(cid:1872)(cid:4667) (cid:1874)= (cid:1857)(cid:1865)(cid:1831)=(cid:1831)