a) Since power = V^2/R , if R were constant the power would decrease by a factor (105/117)^2 = 0.0805. This is a 19.5% reduction in power
b) The electric heater wire in a hair dryer does not have a constant resistance with temperature. The resistance will be somewhat lower at the lower temperature that goes with the reduced voltage. This will raise the power somewhat from the value predicted in part (a)
A 1200 W hair dryer is designed for 117 v.
a) What will be the percentage change in power output if the voltage drops to 105 v.
b) How would the actual change in resistivity with temperature affect your answer.
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