P1- 3.1

Page 1

P1- 3.1- ELECTRICAL APPLIANCES

We use electrical appliances all the time.

They transfer electrical energy into useful energy.

However some of the energy we supply to them is wasted

LIGHT BULB:

Useful energy- Light from the glowing filament

Wasted energy- Energy transfer from the filament heating surroundings

ELECTRIC HEATER:

Useful energy: Energy heating the surroundings

Wasted energy: Light from the glowing element

ELECTRIC TOASTER:

Useful energy: Energy heating bread

Wasted energy: Energy heating the toaster case and the air around it

ELECTRIC KETTLE:

Useful energy: Energy heating the water

Wasted energy: Energy heating the kettle

HAIRDRYER:

Useful energy: Kinetic energy of the fan and energy heating the air

Wasted energy: Sound energy of the fan motor and the energy heating the hairdryer itself

ELECTRIC MOTOR:

Useful energy: Kinetic energy driven by the motor and potential energy of objects lifted by the motor

Wasted energy: Energy heating the motor and sound energy of the motor

COMPUTER DISC DRIVE:

Useful energy: Energy stored in magnetic dots on the disk

Wasted energy: Energy heating the motor that drives the disc