Two portable space heaters are rated at 1500W and 1000W. They are operated for the same length of time each day under identical conditions. Which of the following best explains how their electrical energy consumption compares?
(a) Both heaters use the same energy because they are on for the same time interval.
(b) The 1500W heater uses 33% more energy because the difference in their ratings is 33% of 1500W.
(c) The 1500W heater uses 50% more energy because energy is the product of power and time.
(d) Their energy use depends on the household voltage rather than the power rating on the label.