Energy Transfers in Appliances Flashcards

All 5 cards in this deck

Describe the energy transfer in a mains-powered electric motor, such as in a washing machine.

Energy is transferred electrically from the a.c. mains to the kinetic energy store of the motor, with some dissipated as thermal energy to the surroundings.

Describe the energy transfer in a battery-powered torch.

Energy is transferred from the chemical store of the battery, electrically, to the lamp, which transfers it to the surroundings by light and heating.

Describe the energy transfer in a mains-powered electric kettle.

Energy is transferred electrically from the mains to the heating element, heating the thermal energy store of the water.

What does the power rating of a domestic appliance tell you?

The energy it transfers each second in watts, so a higher power rating means more energy transferred per second.

Does a higher power rating mean an appliance is more efficient?

No. It transfers more energy per second, but it may transfer a smaller share of that energy usefully, so it can be less efficient.