In periods of peak demand, power companies lower their voltage. This saves them power (and saves you money!). To see the effect, consider a 1200-W coffeemaker that draws 10 A when connected to 120 V. Suppose the voltage is lowered by 10% to 108 V. By how much does the current decrease? By how much does the power decrease? (?Caution:? The 1200-W label is valid only when 120 V is applied. When the voltage is lowered, it is the resistance of the toaster, not its power, that remains constant.)

Solution 10P Step 1: 2 The equation for electric power, P = H/t = I R Where, H - Heat produced t - Time of current flow I - Amount of current flowing through the circuit R - resistance offered by the circuit Ohm’s law states that, V = IR, Where “V” is the voltage in the circuit. Step 2: Resistance of the coffee maker, R = V / I Provided, if V = 120 V, I = 10 A Therefore, R = 120 V / 10 A = 12