2. CONTENTS:
Natural Phenomena
Lighting
People’s beliefs on lightning
Benjamin Franklin
Charging by Rubbing
Types of Charges
Facts of Lightning
Protection from Lightning
3. Natural Phenomena
A Natural phenomena is a non- artificial event in the physical sense
therefore not produced by humans
Some common examples of Natural phenomena includes volcanic
eruptions, weather, decay etc..,
Natural phenomena such as Rains are relatively harmless so far as
humans are concerned
6. Lightning
Lightning is a very quick electrical discharge
that occurs between a cloud and the ground,
between two clouds, or within a cloud.
Lightning is also called as an electric spark, but
on a huge scale
7. People beliefs on Lighting And sparks
In Ancient times people didn’t understand the cause of the sparks
They were, therefore afraid of lightning and thought that the wrath of
Gods or Evil spirits was striking them
But Now of course we understand that lightning is caused by the
accumulation of charges in clouds
8. The Sparks that the Greeks knew about
The Ancient Greeks of 600 BC knew that when Amber was rubbed with
the Fur , it attracts light objects such as hair
You might have also seen that your hair is attracted by the cloth of your
dress
If you take off these clothes in dark, you can even see the sparks and can
even hear the crackling sound
9. How Many of you know about The Person Who
DISCOVERED ELECTRICITY??
10. Benjamin Franklin
Benjamin Franklin was born on January 17,1706
As a scientist, he is best known for his experiments with
electricity
In 1752, Franklin showed that lightning and spark
formed are a part of the Natural phenomena
12. Charging by Rubbing (Friction);
Some objects can be charged by rubbing with another object , when the
bodies are rubbed they attract light objects . This is called as Charging by
Rubbing
Ex:-Scale or Comb when rubbed with dry hair obtains charge on surface and
attracts pieces of papers
The charges obtained by rubbing are static charges . They don’t move. When
charges move , it is electric current
Electric current is motion of charges through a conductor
13.
14. Types of Charges ;
There are 2 types of charges .They are positive charge and Negative charge
Two charged bodies may attract or repel each other
Like Similar charges repel each other and unlike charges attract each other
15. So lets us know about the interactions of charges
by some activities…..
16. Like charges Repel each other:
Activity 1: Inflate 2 balloons and hang them in such a way that they don’t
touch each other. Rub both the balloons with a cloth and release them. They
repels each other
Activity 2: Rub a plastic refill with a polythene cover and place it in a glass
tumbler. Rub another plastic refill with polythene cover and bring it near
charged refill. They repel each other
17. Unlike charges attract each other:
Activity : Charge a plastic refill by rubbing it with a polythene and
keep it in a glass tumbler . Change an Inflated balloon by rubbing with
a cloth and bring it near the charged plastic refill . They attract each
other
18. By now you might have understood about the
charges .So now lets know about …..
Some Facts about lightning….
19. Lightning is a real risk; an average of ten deaths and forty injuries from lightning
occur in Florida each year.
Lightning strikes earth a 100 times each second
Average flash will light a 100 watt bulb for 3 months
Lightning is the second largest killer due to storms, exceeded only by floods
Thunder is associated with lightning
20. Protection from Lightning
When You are in Outdoors:
Carrying an umbrella is not safe
If you are in forest take shelter under short trees
If you are in a group, spread out to avoid the current traveling between
group members.
During a lightning storm, immediately find shelter in a substantial building
or a motor vehicle (windows closed)
21.
22. When you are Indoor:
Don't touch electrical equipment such as computers, TVs, or cords. You can
remote controls safety
Stay off corded phones. You can use cellular or cordless phones.
Avoid plumbing. Do not wash your hands, take a shower or wash dishes
Do not lie on concrete floors or lean against concrete walls.