PHYS208 Fundamentals of Physics II

Solution to Ch. 27, 55P:

a. For a 30-day month, cost is $4.32.

b. 144 ohm

c. 0.833 A

d. The lightbulb filament is probably tungsten; the resistivity of metal increases with temperature. Since the temperature of a glowing filament is typically several thousand degrees, the resistance will be less when its turned off.

Last updated Sept. 13, 1997.
Copyright George Watson, Univ. of Delaware, 1997.