What does the author describe?
the characteristics of magnets and magnetic fields
the reasons why some materials are attracted to magnets
the different shapes, strengths, and sizes of magnets
the ways different compasses work to tell the direction
What Is a Magnetic Field?
Magnets are objects that produce an area of magnetic force called a magnetic field. Magnetic fields by themselves are invisible to the human eye. Magnets attract, or pull, objects made of materials that are very attracted to magnets. These materials include iron and nickel. A magnet also reacts to another magnet when they are close enough to each other.
What Are Magnetic Poles?
Magnets come in different shapes, strengths, and sizes. However, they all have a north pole and a south pole. The south pole of one magnet is attracted to another magnet’s north pole. However, the north poles of both magnets would repel, or push, each other away.
What Are the Earth’s Poles?
The earth is like a huge magnet. It has a magnetic field, and it has magnetic North and South Poles. The earth’s magnetic poles are not to be confused with its geographic poles, though.
The earth is tilted on an axis. The geographic North Pole is located at the most northern end of the axis. This place is in the middle of the Arctic Ocean. The geographic South Pole is located at the most southern end of the axis, and this can be found in Antarctica.
The earth’s magnetic poles are in the general direction of the planet’s geographic poles. However, unlike the geographic poles, the magnetic poles are not always in the same place. They are moving slowly.
How Does a Compass Work?
A compass is used to show direction. There are different types of compasses. They include the magnetic compass, the solar compass, and the gyro compass. When people talk about a compass, they often think of the magnetic compass.
A magnetic compass is usually comprised of a magnetized needle and a card with north, south, east, and west printed on it. One end of the needle is attracted to the earth’s magnetic north pole. This end is often painted red. With one end showing you the direction of north, you can use the compass to figure out the other directions, too.
I took the test
B) As the north pole of the electromagnet nears the south pole of the permanent magnet, the current reverses and the poles of the magnets then repel.
As we know that electric motor is based on the concept of torque due to magnetic field on current carrying coil.
Here as the current is passing through the coil the torque on the coil is given as
so here the magnetic field due to coil will continuously repelling the current carrying coil as it will move between the magnetic field so direction of current in the coil will change continuously so that it will always repel by the magnetic field and continuously rotated between the magnets
B.As the north pole of the electromagnet nears the south pole of the permanent magnet, the current reverses and the poles of the magnets then repel.
thank me later
In fact, same magnetic poles repel each other, while opposite magnetic poles attract each other. the magnets on bottom of the train and on top of the railway have the same polarities, so they repel each other and this allows the train to levitate.