Why Doesn't The Bulb Glow?

Description
Drift velocity, Ohm's Law, resistivity are the topics of discussion. Drift velocity has been defined and calculated for Copper wire.To explain conductivity two experiments are shown, one with a candle in front of an electroscope and another where salt is added to increase the conductivity of water.The properties of good and bad conductors are compared. Series and Parallel combination of resistance and effect of temperature on resistance is also included.Finally a question is asked on a bulb experiment based on conductivity of substances.

Prof. Walter Lewin, 8.02 Electricity And Magnetism, Massachusetts Institute of Technology: MIT OpenCourseWare), http://ocw.mit.edu (Accessed June 18, 2011). License: Creative Commons BY-NC-SA: http://ocw.mit.edu/terms/#cc