Ch.8.7 Flashcards
Appliances that work on the heating effect of electric current have ___________________________. They are usually ___________________________.
heating elements, nichrome wires
When _________________ flows through the wires of the heating elements, most of the ___________________________ is converted into ___________________________ for use.
current, electrical energy, thermal energy
Explain how a filament light bulb works.
It uses the heating effect of electric current to work. It contains a long thin tungsten filament. When a current flows through the filament, the filament becomes so hot that it glows and produces light.
When a ________________________________________ is placed near a magnet, a ___________________________ and this force can cause the conductor to _________________. This effect is used in ___________________________.
current-carrying conductor, force is produced, move, electric motors.
Electric motors can convert ___________________________ into ___________________________. They are used to drive the ___________________________ in many ___________________________ we use at home such as ___________________________, ___________________________ and ___________________________.
electrical energy, kinetic energy, moving parts, electrical appliances, electric fans, vacuum cleaners, washing machines
Through the use of different electrical appliances, electrical energy can be ________________ into __________________________________________________________. In other words, electrical appliances are ________________________________________ serving ________________________________________. Name an example.
converted, different forms of energy, energy converters, different purposes
A rice cooker can convert electrical energy into thermal energy for cooking.
Most electrical appliances in our home get power from the ____________________ ____________________. It is generated from ________________________________ and transmitted to our homes through __________________________________.
mains electricity, power stations, electric cables
The mains electricity in Hong Kong has a voltage of _______. This voltage is called the ____________________ ____________________.
220, mains voltage
Why are electrical appliances that can be used in one country may not be suitable for use in another?
This is because the main voltage varies from countries to countries.
To connect an electrical appliance to mains electricity, we need to ________________________________________________.
insert its plug into a mains socket
The plug used in Hong Kong is called a _________________________ as ________________________________________, namely the ____________________, the ____________________ and the ____________________. They fit into the ____________________, the ____________________ and the ____________________ of the mains socket respectively.
three-pin plug, live pin, neutral pin, earth pin, live hole, neutral hole, earth hole
What are the colours of the wires of the earth wire, live wire and neutral wire respectively?
green-and-yellow, brown and blue
In fact, only the live and neutral wires are responsible for ________________________________________. The live wire ____________________________________________________________. The neutral wire ____________________________________________________________. The earth wire is ________________________________________.
delivering electricity to electrical appliances
carries the voltage that drives the current flowing through the appliance
provides a return path for the current to complete the circuit
a safety device only
