discussion about magnet
TRANSCRIPT
Introduction of Magnets
Presented by:Challa. Vyshnavi Reddy,
6th ClassD/O Madhava ReddyKeshava Reddy School-Kandi, SANGAREDDY,TELANGANA, INDIA
How magnet was found?
In Asia there is a place called magnesia. There lived a sheep herder. Once he took his sheep's and went for a walk then he sat at a stone he had a wooden stick and at end there is an iron cap. As he sat on the stone he was going the stick is attached to the stone. Then he founded the magnet.
SUBSTANCES
MAGNETIC SUBSTANCES
• Ex- steel, cobalt, iron etc
NON-MAGNETIC SUBSTANCES
• Ex- wood, plastic, paper etc
MAGNETIC SUBSTANCES
FERRO MAGNETIC STUBSTANCES
• The substances which attracts to magnet strongly
PARA MAGNETIC SUBSTANCES
• The substances which attracts to magnet weakly
DIA MAGNETIC SUBSTANCES
• The substances which repels to the magnet
FERRO MAGNETIC SUBSTANCES Ex: steel, iron , cobalt, nickel etc
PARA MAGNETIC SUBSTANCES Ex: aluminum , chromium ,
manganese etcDIA MAGNETIC SUBSTANCES Ex: gold, mercury, water, silver
etc
PROPERTIES OF MAGNET
Attractive Property
Navigation Property
Same Attraction Opposite
Repel
Opposite Attraction Same
Repel
Opposite Attraction And Same Repel
Unlike poles:The poles are unlike they will attract to each other
IN CHINA THERE IS A STORY
In china there is a sea in this sea there is a black stone. When people goes towards sea the ship dashed to this stone and collapse the ship. Then they found the magnet. They also named this stone as lode or lead stone.
To Know the Direction with Magnet
When the sharp end of a magnet
shows the north pole. Chinese
have been invented as the stone
always collapse the ships of
people who goes into the sea. So
they al so saw the directions of
magnet. As the base at south
POLES:
1. Geometric PolesThe extreme ends of the poles
2. Magnetic Poles
The inside poles of magnet
End Points
MAGNETIC AXIS
The horizontal line drawn from north pole to south pole
EQULATERAL LINE
The vertical line perpendicular drawn to divide north pole and south pole
MAGNETIC LENGTH The distance between north
pole to south pole
GEOMETRIC LENGTH
The distance between two geometric poles
Magnetic North And South Poles
Take a magnet and inflate it. The sharp point of magnet goes to geometric north pole called magnetic north pole and the base of the magnet shows the geometric south pole called magnetic south pole.
RELATION BETWEEN MAGNETIC AND GEOMETRIC LENGTH
Magnetic length =5/6 x geometric length EXAMPLE 1. AB =12cm, NS =? 5\6 X 12 NS=10
SINGLE TOUCH METHODPlace a steel bar on a table. Place a magnet and one end of its pole is placed .Stroke the magnet from one end to another end of a steel bar and lift the magnet and place again from where it starts and repeat the process.
DOUBLE TOUCH METHOD
Place a steel bar and place two magnets on the steel bar at the center of the bar. Stroke the magnets to the opposite sides of the magnets. Repeat the same process
ELECTRICAL METHODInsulated copper wire is wound on a nail the ends of the copper wire connected to the battery. In the battery the dry cells are places in +ve and –ve terminals in series.
To prove these artificial magnets have the attractive property
Take some iron nails and keep near to the bars if the iron nails attract then we can prove that they are artificial magnet
DE MAGNETIC INDUCTION Process of losing the attractive
property of magnet Ex: By Heating , Hardly Handling,
Throwing etc.
MAGNETIC INDUCTION
Take a magnet and a iron nail another nail attracts to the first nail because the attractive property gains to the nail.
TO KNOW THE MAGNETIC FIELD:
Take a magnet and keep a
paper on a magnet and keep some iron nails on a paper and gently move the paper then the iron nails comes to the shape of the magnetic fields.
EXPERIMENT:
PROPERTIES OF MAGNETIC LINES
North to south pole around magnet
Direction of magnetic field
They don’t intersect each other
Density of magnet gives the
intensity of magnetic field
NORTH AND SOUTH POLE AROUND MAGNET
The magnetic field around goes from north pole to south pole from out but inside south pole to north pole.
Direction of Magnetic Field
IF we draw a straight line from any line from a Magnetic Field it is Called Tangent
They doesn't intersect each other
If the magnetic lines intersect there will be 2 directions but it should has only 1 directions
Density of magnet gives intensity of magnetic field
When lines are more then intensity is more. If lines are less intensity is less
MAGNETIC KEEPERS When magnets exposed to air it
starts demagnetize so keep 2 soft iron pieces so if the attractive property looses it goes to the iron pieces
Inverse Square Law of Magnetism
Take 2 magnets and place them on a table so now the
distance of the monopoles of magnet is considered as ‘d’
and the attraction or repulsion is force the product of pole
strength is m1m2.Delivation is F is inversely proportional
to the product of pole strength that is F∞ m1m2. As the
force is directly proportional to square distance between
the distance of the monopoles of magnet that is F∞1\d2 .
Then F∞m1m2 \d2 we should not use proportional symbol
we should a constant so we use K because it is a
proportionality constant then F=km1m2\d2 . As k=10-7.