1. Ch. 19-2

2.  The opposition to the motion of charge in a conductor.  For most metals, resistance is constant over a wide range of applied potential differences.  I = amperes (A) V = volts (V) R = ohms ( Ω )

3.  Resistance depends on: Length Cross sectional area temperature Material

4.  Sample Problem 19B pg. 702

5.  Material that has zero resistance below a certain critical temperature.

6. 19-3

7.  Rate at which charge carriers do work.  P = Watts (W) I = Amperes (A) V = Volts (V)

8.  Power companies charge for energy in kilowatt-hours (kWh)

9.  Sample Problem 19D pg. 712