Energy Transfers in Everyday Appliances

• everyday electrical appliances are designed to bring about energy transfers
• the amount of energy an appliance transfers depends on how long the appliance is switched on for and the power of the appliance
• in a torch, the energy stored in the battery is used to heat up the filament of the bulb
• in a vacuum cleaner, energy is usefully transferred from the power station to make the motor spin. some of the energy is transferred less usefully into the room through sound and heat
• work is done when charge flows in a circuit
• in electrical components, the power relates to the potential difference across the component and the current through it. if either the p.d. or current increases, the power increses
• the power of an appliance is the amount of energy that it transfers per second