Domestic Electrical Appliances (English subtitles available)
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This programme is divisible into 6 segments as follows:
1. Heating effect of current
Experiment was carried out to demonstrate that when a current passes through a resistor, the resistor will glow and gives out heat and light. When an electric current passes through a resistance coil, the electric energy is converted into heat energy. This is known as the heating effect of current.
The heating effect increases with the resistance of the metal wire. The metal wire with a high resistance is known as a resistance coil, or a heating coil because it can heat up.
2. The application of heating effect in electrical appliances
The programme introduces various types of electrical appliances that apply the heating effect of current. It includes electric heater, hair dryer, electric radiator, toaster, electric iron and cooker.
3. Magnetic effect of current
Experiment was carried out to demonstrate the relationship between current and magnetic effect.
When an electric current passes through a conducting wire, magnetic effect can be generated. The stronger the electric current, the stronger the magnetic effect generated. The generation of magnetic effect by a current carrying conducting wire is known as the magnetic effect of current.
4. Electromagnet
Experiment was carried out to demonstrate that when current passes through a solenoid, it will produce a magnetic effect similar to a bar magnet. A device that generates a magnetic effect after being connected to a power supply is known as an electromagnet.
The programme also introduces the application of electromagnet in doorbell and moving coil loudspeaker.
5. Motor
Experiment was carried out to illustrate that a current carrying wire can experience a magnetic force when it is placed in a magnetic field. It is a foundation used to explain the principles of a motor.
The programme introduces different electrical appliances that a motor is installed inside.
6. Power of electrical appliances
Power is the quantity of electric energy supplied to the appliance in one second. The unit of powder is watt and its symbol is "W".
In the programme, the power of different appliances are compared. How electricity bill calculated is also illustrated.
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