Sakshi Education
Thunder and Lightening
The clouds formed in the sky consists of millions and millions of water drops and tiny ice pieces. These clouds move suddenly when there are pressure differences in the atmosphere and the water drops and ice pieces in them will get scattered. At that juncture they undergo friction and the clouds will acquire electric charge.
Now, let us study certain facts about electric charges. We know that when a glass rod is rubbed with silk or fur, the rod attracts small pieces of paper and sawdust. This property possessed by glass rod because of friction is called 'electricity' and charges acquired by it are called 'electric' charges. The electric charges are of two kinds. One is called positive charge and the other negative charge. A body with electric charge is brought nearer to another body (with out a charge), though they are not touching each other, the other body will acquire the opposite charge. This is called electrostatic induction.
In clouds also, because of friction, if the upper surface of a cloud gets positive charge, its lower surface acquires negative charge. Because of electrostatic induction, the earth and the objects on it will acquire opposite charge ie., positive charge. At this stage, the electricity flows from the clouds towards the earth. This called electrical discharge which is 'Lightening'.
The sound produced by lightening is called 'Thunder'. Lightening may occur between two clouds which are oppositely charged. When this lightening strikes the earth severely it is called thunderbolt. While the thunderbolt strike the ground the temperature of the air around it will acquire a severe temperature nearly 30,000 °C and this temperature is five times greater than the surface temperature of the sun. This heat energy expands the air all of sudden with greater speed. This speed is many times greater than the speed of sound. This severe sound produced because of the expansion of air all of a sudden is what we call 'Thunder'. Though the lightening (with of high intensity) and 'Thunder' takes place at the same time and at the same place, we see lightening earlier than hearing the severe sound of thunder because, the velocity of light is many times greater than that of sound.
The clouds formed in the sky consists of millions and millions of water drops and tiny ice pieces. These clouds move suddenly when there are pressure differences in the atmosphere and the water drops and ice pieces in them will get scattered. At that juncture they undergo friction and the clouds will acquire electric charge.
Now, let us study certain facts about electric charges. We know that when a glass rod is rubbed with silk or fur, the rod attracts small pieces of paper and sawdust. This property possessed by glass rod because of friction is called 'electricity' and charges acquired by it are called 'electric' charges. The electric charges are of two kinds. One is called positive charge and the other negative charge. A body with electric charge is brought nearer to another body (with out a charge), though they are not touching each other, the other body will acquire the opposite charge. This is called electrostatic induction.
In clouds also, because of friction, if the upper surface of a cloud gets positive charge, its lower surface acquires negative charge. Because of electrostatic induction, the earth and the objects on it will acquire opposite charge ie., positive charge. At this stage, the electricity flows from the clouds towards the earth. This called electrical discharge which is 'Lightening'.
The sound produced by lightening is called 'Thunder'. Lightening may occur between two clouds which are oppositely charged. When this lightening strikes the earth severely it is called thunderbolt. While the thunderbolt strike the ground the temperature of the air around it will acquire a severe temperature nearly 30,000 °C and this temperature is five times greater than the surface temperature of the sun. This heat energy expands the air all of sudden with greater speed. This speed is many times greater than the speed of sound. This severe sound produced because of the expansion of air all of a sudden is what we call 'Thunder'. Though the lightening (with of high intensity) and 'Thunder' takes place at the same time and at the same place, we see lightening earlier than hearing the severe sound of thunder because, the velocity of light is many times greater than that of sound.
Prof. Laxmi... Emani
Published date : 07 Dec 2012 03:28PM
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