Some natural phenomena

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Some natural phenomena:

Some natural phenomena By Anurag Pandey Class – VIII-B School-Army Public School Golconda

ARMY PUBLIC SCHOOL Golconda:

ARMY PUBLIC SCHOOL Golconda

Electrically neutral state of matter:

Electrically neutral state of matter Most of the matters are present in electrically neutral state in nature. To understand this, let us recall the basics of atomic structure. An atom is made up of electrons, protons and neutrons. An electron carries a negative charge, a proton carries a positive charge and there is no charge on a proton. In an electrically neutral atom, the number of electrons is equal to the number of protons. Thus, the equal numbers of negative and positive charges balance each other. Most of the matters remain in electrically neutral state because of this reason. Transfer of Charge: When certain objects are rubbed against another object, electrons may get transferred from one object to another. If an object loses some electron, it is left with surplus number of protons. Thus, this object becomes positively charged. If an object gains electrons, it now has surplus number of electrons. Thus, this object becomes negatively charged. The transfer of charges is responsible for static electricity in various objects. Static electricity is the main reason of lightning.

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The electron always has a "-", or negative, charge. The proton always has a "+", or positive, charge. If the charge of an entire atom is "0", or neutral, there are equal numbers of positive and negative charges. Neutral atoms have equal numbers of electrons and protons. The third particle is the neutron.

Interaction of charges:

Interaction of charges A charged object attracts an uncharged object: Take a ball pen refill and rub it against a woollen cloth. Bring this refill near bits of paper. It is observed that the refill attracts the bits of paper. This activity shows that a charged object attracts uncharged object. Charge comb attracts bits of paper Take a comb and rub it vigorously in your hairs. Your hairs should be completely dry during this activity. Bring this comb near bits of paper. It is observed that the refill attracts the bits of paper. This activity shows that a charged object attracts uncharged object. Like charges repel each other: Take two plastic balls and suspend them near each other. Rub a glass rod to induce charge in it. Touch both the balls with this glass rod. It is observed that the plastic balls move away from each other. This activity shows that like charges repel each other. Unlike charge repel each other and Like charge Attracts each other Unlike charges attract each other: Take two plastic balls and suspend them near each other. Rub a glass rod with a silk cloth. Touch one of the balls with the glass rod and touch another ball with the silk cloth. It is observed that both the balls move towards each other. This activity shows that unlike charges attract each other.

Electroscope::

Electroscope: Electroscope is a simple device which is used to test the presence of charge in an object. The gold-leaf electroscope was developed in 1787 by a British scientist named Abraham Bennet. Gold and silver are among the best conductors of electric current and hence leaves of these metals are used in electroscope . Structure of Electroscope: It is made of a glass jar. A vertical brass rod is inserted into the jar through a cork. The top of the brass rod has a horizontal brass rod or a brass disc. Two gold leaves are suspended from the brass rod; inside the jar. Working of Electroscope: When the brass disc of the electroscope is touched with a charged object, electric charge gets transferred to the gold leaf through the rod. This results in the gold leaves moving away from each other. This happens because both the leaves have similar charges. Charging: Transfer of charge from one object to another is called charging. In case of the gold leaves; charge is transferred through the brass rods. Hence, it can be said that charging can happen through metals.

conclusion:

conclusion In the above activity, the gold leaves resume their normal position after some time. This happens because they lose their charge. This process is called electrical discharge. The gold leaves would also be discharged when someone touches the brass rod with bare hands. In that case, the charge is transferred to the earth through the human body

lightning:

lightning Lightning is observed as a bright streak of light during a thunderstorm. Lightning is always accompanied by the sound of thunder. The transfer of charge from clouds to the earth or from cloud to cloud is called lightning. In simple words; lightning is an electric spark which happens on a grand scale in the sky.

Safety during lightning:

Safety during lightning No open place is safe during lightning and hence a home or any other building is the safest place during lightning. The first sound of thunder is like a warning call for lightning. Hence, one should rush to a building soon after hearing a sound of thunder. One should come out of home only a few minutes after the last sound of thunder. You should not carry an umbrella (with a metallic handle) during thunderstorm. Metallic handle can be a potential target for lightning. Tall trees and other tall structures are more prone to be hit by lightning. If you are caught in the open, try to hide under a short tree. If you are in open and have no place to hide, then crouch on the ground and keep your head between your knees and hands. Don’t take shower during lightning. Use of phone should be avoided during lightning. Television should be disconnected from the antenna. Avoid operating the electric switches during lightning

Lightning conductor:

Lightning conductor This is a simple device which protects a building from being hit by lightning. It is composed of a vertical metallic rod which usually has a trident at the top. The base of the metallic rod is attached to thick metallic wire; which goes very deep inside the earth. This metallic wire provides a passage for earthing. When lightning strikes, electric charge goes to the lightning conductor and is then goes to earth. Thus, a lightning conductor helps in preventing any damage to the building.

earthquake:

earthquake Sudden shaking of the earth; which lasts for a very short duration is called earthquake. Tectonic Plates: The crust of the earth is composed of several pieces of landmass. These are called tectonic plates. The tectonic plates are in continuous motion. They keep on brushing against each other or striking each other. When a tectonic plate brushes against another or strikes another tectonic plate; it results in vibrations in the tectonic plates. These vibrations are experienced by us in the form of an earthquake.

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Steps of earthquake

Protection Against Earthquake: :

It is impossible to predict an earthquake and hence we need to take several precautionary measures to avoid or minimize the damage which may happen because of earthquake. Some of the preventive measures are as follows: Buildings should be made quake proof. Engineers and architects are the experts who can give suitable advice in this regard. Light-weight materials should be used for making the buildings in earthquake prone areas. Cupboards should be fixed to the walls so that they do not fall on someone during an earthquake. People should be made to practice drills for earthquake. Such drills should be frequently organized in schools and at public places. In case of an earthquake, you should hide under a table or any other similar structure. If you are in bed, then keep a pillow over your head and do not move out of the bed. If you are in an open area, try to move away from buildings and other structures. Proper installation of fire-fighting equipment should be ensured in buildings. Fire due to short circuit and gas leakage is quite common during an earthquake. Protection Against Earthquake :

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