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Some natural phenomena

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Some natural phenomenaON A STORMY NIGHT,WE OFTEN HEAR A

LOUD NOISE OF THUNDER AND SEE A BLUISH

-WHITE FLASH OF LIGHT IN THE SKY.HAVE YOU EVER WONDERED WHAT

THESE ARE AND HOW THEY ARE CAUSED?THESE ARE SOME NATURAL PHENOMENA THAT OCCUR IN NATURE. SOME OTHER

NATURAL PHENOMENON ARE EARTHQUAKES ,TSUNAMI,ETC.

LET US READ ON TO LEARN MORE ABOUT LIGHTNING & EARTHQUAKES.LET US

ALSO FIND OUT HOW ELECTRIC CHARGES ARE LINKED WITH LIGHTNING.

Some natural phenomena example :-

Earthquakes lightning

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Electric charges

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Electric chargesELECTRIC CHARGE IS THE PHYSICAL PROPERTY OF MATTER THAT CAUSES IT TO EXPERIENCE A FORCE WHEN CLOSE TO OTHER ELECTRICALLY CHARGED

MATTER. THERE ARETWOTYPES OF ELECTRICCHARGES  POSITIVE AND NEGATIVE.

POSITIVELY CHARGED SUBSTANCES ARE REPELLED FROM OTHER POSITIVELY CHARGED SUBSTANCES,

BUT ATTRACTED TO NEGATIVELY CHARGED SUBSTANCES; NEGATIVELY CHARGED SUBSTANCES

ARE REPELLED FROM NEGATIVE AND ATTRACTED TO POSITIVE. AN OBJECT WILL BE NEGATIVELY

CHARGED IF IT HAS AN EXCESS OFELECTRONS, AND WILL OTHERWISE BE POSITIVELY CHARGED OR

UNCHARGED. 

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Electric charges example:-

Electric charges

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Charging a body

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Charging a body

An electrically neutral object can be charged by various

methods.The various methods are:-

Charging by frictionCharging by conductorsCharging by induction

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Transfer of charges

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WE CAN TRANSFER ELECTRIC CHARGE FROM A CHARGED

OBJECT TO A NEUTRAL OBJECT THROUGH A METAL

CONDUCTOR.A DEVICE CALLED ELECTROSCOPE WHICH IS

USED TO DETECT AND MEASURE ELECTRIC CHARGE IS

BASED ON THIS PRINCIPLE.

Transfer of charges:-

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Electroscope pic. :-

electroscope

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Lightning

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THIS STREAK OF BRIGHT LIGHT IS

KNOWN AS LIGHTNING AND THE PROCESS IS CALLED

ELECTRIC DISCHARGE.

Lightning:-

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Lightning pic. :-

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Lightning conductors

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LIGHTNING CONDUCTOR A STRIP OF METAL, GOING FROM

THE HIGHEST POINT OF A BUILDING TO THE GROUND, THAT PREVENTS LIGHTNING

FROM DAMAGING THE BUILDING BY TAKING THE

ELECTRICITY TO THE GROUND BEFORE IT CAN REACH A

DANGEROUS LEVEL

Lightning conductors:-

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spikesStorm cloud

Tall building

Stream of

positive ions

Electrons repelled

to the earth

Copper strip

Diagram Lightning conductors:-

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Safety during lightning

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Safety during lightning :-

DO NOT REMAIN IN AN OPEN PLACE.

STAY AWAY FROM WATER.

DO NOT STAND UNDER A TREE

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earthquakes

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AN EARTHQUAKE (ALSO KNOWN AS A QUAKE, TREMOR OR

TEMBLOR) IS THE RESULT OF A SUDDEN RELEASE OF ENERGY IN

THE EARTH'S CRUST THAT CREATES SEISMIC WAVES. THE

SEISMICITY, SEISMISM OR SEISMIC ACTIVITY OF AN AREA REFERS TO THE FREQUENCY, TYPE AND SIZE OF EARTHQUAKES EXPERIENCED

OVER A PERIOD OF TIME.

Earthquakes :-

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Earthquakes pic. :-

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Structure of the earth

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Structure of the earth :-THE EARTH CONSISTS OF THREE PARTS:-CRUST= IT IS THE OUTERMOST SOLID

SHELL OF THE EARTH.IT IS OF NON-UNIFORM THICKNESS AND IS THINNER AT THE OCEAN FLOOR. IT IS COMPOSED OF A

VARIETY OF ROCKS.MANTLE=IT IS LIES JUST BELOW THE CRUST.

IT CONSISTS OF SEMI-SOLID ROCKS,IRON,MAGNESIUM AND CALCIUM.

CORE=IT IS THE INNERMOST PART OF THE EARTH AND IS DIVIDED INTO TWO SECTIONS

THE OUTER CORE CONTAINS IRON AND NICKEL IN MOLTEN STATE.THE INNER CORE IS BELIEVED TO BE MADE OF COMPRESSED IRON

AND NICKEL IN SOLID FORM.

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Structure of the earth pic. :-

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Occurrence of earthquakes

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AN EARTHQUAKES IS A SUDDEN

MOVEMENT OR A DISTURBANCE IN

THE LITHOSPHERE.

Occurrence of earthquakes :-

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Measuring intensity of earthquakes

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Measuring intensity of earthquakes :-

THE INSTRUMENT USED TO MEASURE SEISMIC WAVES IS CALLED A SEISMOGRAPH. THE

RECORD OF THE SEISMOGRAPH ON THE

GRAPH PAPER IS CALLED SEISMOGRAM.

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Measuring intensity of earthquakes pic. :-

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Protection against earthquakes

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Protection against earthquakes :-WHILE CONSTRUCTING A BUILDING, CONSULT A QUALIFIED ARCHITECT AND CIVIL ENGINEER FOR TIPS ON HOW TO MINIMIZE THE EFFECT OF

AN EARTHQUAKES ON THE STRUCTURE.

REPAIR ANY CRACKS IN THE WALLS OR CEILINGS.

KEEP FIRE FIGHTING EQUIPMENTS HANDY AS SOME BUILDINGS MAY

CATCH FIRE DUE TO AN EARTHQUAKE.

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Protection against earthquakes pic. :-

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NAME:-CLASS:-8TH ROLL NO:-