Electric Cell and Torch Bulb


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Electric Cell
An electric cell is a device that supplies electrical energy to devices that function using electricity. It provides electricity to a number of devices, such as toys, alarm clocks, pocket radios and cameras. An electric cell  consists of two terminals: a positive terminal and a negative terminal. It has a cap, just under which there is a plus sign. This is the positive terminal of the cell. At the other end of the cell, there is a flat metallic disc with a minus sign just above it. This metallic disc is the negative terminal of the cell. These terminals of the cell can be used to connect it to various devices. Inside a cell, there is dark powdery stuff, which is the chemical that helps the cell to provide electricity to the device it is connected to. When a cell is connected to a device, the strength of the chemical decreases. Finally, when the entire energy of the chemical is spent, the device connected to the cell stops functioning. A rechargeable cell or a storage battery can be recharged and can be used again.

Torch Bulb
A torch bulb consists of two terminals and a filament. The filament is a spirally wound wire inside the bulb supported by two thick wires at its ends. When the positive and the negative terminals of an electric cell are connected to the two terminals of a bulb, electricity passes through the filament and it starts glowing. The terminals of the bulb are fixed in such a way that they do not touch each other. In recent years, a different type of bulb has become popular - the compact fluorescent lamp (CFL). It is an energy-saving bulb, which has a longer life than an ordinary bulb.


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Activities & Simulations

Activity 1

Woodlandgrange has developed an interactive activity which enables one to understand the parts used in making  a torch and their functions. One can switch on and off by clicking the switch. There is an interactive labelling test too.

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