During a period of high power demand,the voltage output of the power company is reduced by 5.0%.By what percentage is the power in a resistor decreased?
A)2.5%
B)5.0%
C)10%
D)15%
E)90%

Question

Quizplus · Accepted Answer

The power in a resistor (P) is given by the formula P = V^2/R, where V is the voltage across the resistor and R is the resistance. If the voltage is reduced by 5%, the new voltage is 0.95V. Substituting into the power formula gives the new power as P_new = (0.95V)^2/R = 0.9025V^2/R. This is a reduction to 90.25% of the original power, which means the power is decreased by 100% - 90.25% = 9.75%, which is approximately 10%.

During a Period of High Power Demand,the Voltage Output of the Power