of 34 /34
SOME NATURAL PHENOMENA Created by :- Arpit and Pritish 9/24/2013 1 Some Natural Phenomena

Some Natural Phenomena class 8 EVS by arpit

Embed Size (px)

DESCRIPTION

Class 8th EVS lesson contains about electroscope lightning earthquake positive charge

Citation preview

Page 1: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 1

SOME NATURAL

PHENOMENACreated by :-

Arpit and Pritish9/24/2013

Page 2: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 2

Some natural phenomena

9/24/2013

Page 3: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 3

Content Electric Charge

Electroscope

Lightning

Earthquakes

9/24/2013

Page 4: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 4

Electric Charge It was discovered about 2500 yrs

ago It was discovered by a Greek

scientist called Thales. An object without any charge is

called uncharged object And the object with an electric

charge is called charged object The process of giving charge is

called charging the object.

9/24/2013

Page 5: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 5

Electric Charge Twentieth-century experiments

 demonstrated that electric charge is quantized.

The charging of an object by rubbing it with another object is charging by friction.

The electric charges generated by rubbing (or friction) are static electric charges.

9/24/2013

Page 6: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 6

electroscope A device used for detecting

electric charge on a object  It was the first

electrical measuring instrument

The first electroscope, a pivoted needle called the versorium

It was invented by British physician William Gilbert around 16009/24/2013

Page 7: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 7

electroscope The gold-leaf electroscope was

developed in 1787 by British clergyman and physicist Abraham Benet

The electroscope can also be charged without touching it to a charged object, by electrostatic induction

The electric potential or voltage of an object equals its charge divided by its capacitance, so electroscopes can be regarded as crude voltmeters

9/24/2013

Page 8: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 8

Images for Electroscope

9/24/2013

Page 9: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 9

lightning

9/24/2013

Page 10: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 10

Lightning The bright flash of light which we see in the

clouds is called lightning. There are three types of lightning:

1. Cloud to itself (intra cloud or sheet lightning)2. From one cloud to another (Cloud to cloud or

CC)3. Cloud to the ground (CG)

The electric nature of lightning was established by Benjamin Franklin

 Lightning occurs approximately 40–50 times a second worldwide, resulting in nearly 1.4 billion flashes per year.

9/24/2013

Page 11: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 11

lightning  It is a massive electrostatic discharge

between electrically charged regions within clouds , or between a cloud and the Earth's surface.

The lightning which usually occurs within the cloud in the sky is called ‘sheet lightning’

And the lightning which usually occurs between a cloud and the earth or the objects on it is called 'fork lightning’.

9/24/2013

Page 12: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 12

lightning The science of lightning is

called fulminology. The fear of lightning is

called astraphobia. Lightning is not distributed evenly

around the planet. About 70% of lightning occurs over

land in the tropics where atmospheric convection is the greatest

9/24/2013

Page 13: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 13

Pictures for lightning

9/24/2013

Page 14: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 14

Images for fork lightning

9/24/2013

Page 15: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 15

Images for sheet lightning

9/24/2013

Page 16: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 16

dangers of lightning When a lightning strikes the earth

it causes a lot of damage to the property (buildings ,etc.)

Although lightning is an beautiful phenomena but it is very dangerous

Before 4 days lightning was stroked 3 times in lake forest at Chicago

9/24/2013

Page 17: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 17

Images of damage caused by lightning

9/24/2013

Page 18: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 18

Lightning rod Lightning conductor is a device

used to protect a building from the effects of lightning

The function of lightning conductor is to conduct any lightning strikes safely to the earth(without causing any damage to the building).

The lightning rod was invented by Benjamin Franklin in North America in 17499/24/2013

Page 19: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 19

Images of lightning rod

9/24/2013

Page 20: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 20

Measures to protect ourselves from lightning Don't take shelter in open space, a house

or a building will be a safe place Open vehicles like motorbikes ,scooters

,tractors are not safe We should avoid raising umbrella over

head during lightning, as because it lightning may strike at the top of the umbrella .

TV antennas are more prone to lightning, so we should switch off our TV sets during lightning .

9/24/2013

Page 21: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 219/24/2013

Page 22: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 22

earthquake The sudden shaking (or

trembling) of the earth’s surface which lasts for a short time is called earthquake .

It is a destructive natural phenomena which cannot be predicted in advance

Earthquakes are measured using observations from seismometers.

Earthquakes can also cause floods , landslides ,tsunamis.

9/24/2013

Page 23: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 23

why do earthquake occur The earthquake occur due to

these reasons:I. Plates slide past one anotherII. Collide with one another

New mountain formed as the two plates collide

On plate of earth’s crust

Another plate of earth’s crust

9/24/2013

Page 24: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 24

Seismic zone The weak zone of earth’s crust

are called seismic zone

9/24/2013

Page 25: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 25

Images for earthquake

9/24/2013

Page 26: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 26

seismograph Seismograph is an instrument which

measures and records the magnitude of an earth quake in terms of shock waves it produces.

9/24/2013

Page 27: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 279/24/2013

Page 28: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 289/24/2013

Page 29: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 29

Q. Fill in the blanks

1. Like charges ; unlike charges .

2. The sudden shaking of land is called an .

3. the bright flash of light that we see in the sky is called .

9/24/2013

Page 30: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 30

1. Like charges repel ; unlike charges attract

2. The sudden shaking of land is called an earthquake.

3. the bright flash of light that we see in the sky is called lightning.

9/24/2013

Answers

Page 31: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 31

Q. Match the pairs

‘A’ ‘B’1. Earthquake Golden

leaves

2. Lightning Seismograph

3. Electroscope Lightning rod

9/24/2013

Page 32: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 32

conclusion

From this presentation we learnt about the various natural phenomena and there effects and how they are caused

Although some phenomena are beautiful, but they are dangerous

9/24/2013

Page 33: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 339/24/2013

Page 34: Some Natural Phenomena class 8 EVS by arpit

Some Natural Phenomena 349/24/2013

Some Natural PhenomenaMade by :

Arpit and pritish