posted by Raven .
Julia and Wayne heat their house during the winter with an electric heater. The thermostat on the heater is set to 20 °C and the thermostat is cycling on and off as it keeps the room temperature stable. Julia walks out of the room leaving the light on. Wayne tells Julia that she is wasting electricity. Julia says that she’s not.
She is probably not, as the energy in the light bulb is just adding to the heat in the room, causing the heater to cycle on less often.