Name: Control of Pollution Due to Burning of Fossil Fuels
Uploaded: 2019-07-19
Duration: 6 min 34 s
Description: When fossil fuels are burned, they release nitrogen oxides. Let's see the different methods used to control the pollution generated by the exhaustion of foss...

Question

What is a solar cell? Draw a labelled diagram of a solar cell.

Accepted Answer

Solar cell is a device that converts solar energy directly into electricity. It is also called photovoltaic cell. Solar cells are usually made from altered silicon. Silicon is a semiconductor whose ability to conduct electricity is less than that of a conductor. But when certain substances are added to silicon, it becomes a better conductor of electricity. This property is used in making solar cells. Solar cells usually consist of a sandwich of a silicon arsenic layer and a silicon-boron layer. However, the amounts of arsenic and boron in the two layers are very small.

When sunlight falls on a typical solar cell, it develops a voltage of 0.5 - 1.0 V due to movement of loosely held electrons in the silicon atoms and produces about 0.7 W of electricity. The power generated by the solar cell depends on its surface area. The greater the surface area, the greater is the solar energy collected and hence, greater is the power produced. A single solar cell generates little power which is much less than that produced by a dry cell. Small solar cells are hence used only to power electronic devices like calculators and watches which require very little power to run. This arrangement of solar cells is called a solar cell panel. A solar cell panel has solar cells connected in such a way that a large potential difference develops which generates sufficient power for many applications.

What is a solar cell? Draw a labelled diagram of a solar cell.

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