electric current
TRANSCRIPT
These appliances work on the electricity provided by government company. Or on various types of
electricity provided. Both of these types of electricity is called Electric current.
.
The field through which electric current flows is called electric field.
Source of electric current (either Government or electric cell) in electric field, transmission lines, electrical
appliances, and a switch to start/stop electric current.
Electric current flowing through the field generates current of charges(electron) or flow. When silk cloth and glass rod or woollen cloth and ebonite rod are rubbed electric charges are produced. But the charges remain still on those bodies. With the help of electric cell these static
charges are set in motion and electric current is generated.
Types of electric cell
1) Simple Cell> 2) Leclanche Cell> 3) Dry Cell> 4) Nickel-Cadmium
Cell
5) Button Cell
Simple Cell (Voltas Cell)Positive pole - Copper rod
Negative pole – Zinc rod
Chemical – Dilute Sulphuric acid.
Leclanche> Cell (Cannot be recharged)
Positive pole - Cylindrical Porous pot with mixture of Manganese dioxide and carbon
Negative pole - Zinc Rod
Chemical– Ammonium chloride>
Dry cell> (Cannot be recharged)
Positive pole – Carbon rod
Negative pole – Zinc can Chemical – Manganese dioxide, graphite, zinc chloride and ammonium chloride
Nickel-Cadmium Cell> - (Can be recharged)
Positive pole - Nickel
Negative pole - Cadmium
Chemical - Potassium Hydroxide>
Button Cell( Lithium Cell)Cannot be recharged
Positive pole - Carbon
Negative pole - Lithium Iron Phosphate
While electric current flows through a conductor, it behaves
like a magnet. Hence a magnetic field develops around it, which causes the
deflection of magnetic needle.
Electro-Magnetic Induction- If there is a change in the magnetic field associated with a coil of wire ,electric
current begins to flow through the coil. Such a current is called induced current. This phenomenon of the change
in a magnetic field and the electric current that it generates is called electro-magnetic induction
The working of electric motor is based on the principle of
electro magnetic induction..
When electric current is passed through a conductor, it
works like a magnet. Such magnets are called electro-magnet.
Uses of Electro-Magnet – Loudspeaker, Telephone, Electric crane.Electric bell also works on the principle electro-magnet .
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Electrical Conductors- Substances through which
electricity can flow easily are called Electrical Conductors.
Example : All metals
Electric insulators – The substances which do not carry
electric current are called Electric insulators. Example: Glass, Paper, Rubber, Plastic, stones, etc.