What is a magnetic pole?
A magnetic pole is a location on a magnet that produces a magnetic force. In the case of a bar magnet, the magnetic poles are located at the ends of the magnet. Like poles (two north or two south poles interacting) exert a repulsive force, while unlike poles (a north to a south interacting or vice versus) exert an attractive force on each other.
What is a monopole magnet?
A monopole magnet is a fictious magnet that only has one pole, either a north or a south pole. Making a monopole magnet is not possible. It is possible to make a monopole electric charge, such as a positive or negatively charged object.
What is a magnetic field?
A magnetic field is the space that shows the magnetic force around a magnet. The magnetic field is illustrated by lines that show where a north monopole magnet would be attracted. The closer the magnetic field lines are together, the stronger the magnetic force.
What causes a magnetic field?
A magnetic field is produced by a moving electric charge. In a bar magnet, the electrons of atoms that make up the magnet are constantly moving. Each electron is spinning in one direction, either clockwise or counterclockwise. Since the charge is moving, a magnetic field is created by the electron’s spin. When many electrons all spin in the same direction, a magnetic field is produced and results in the billions of atoms producing a magnetic domain. When many domains align, the result is a bar magnet.
What is the relationship between current and a magnetic field?
When current flows through a wire, a magnetic field is created around the wire. The greater the current, the greater the magnetic field.
How does coiling a wire affect the magnetic field strength?
Coiling or looping a wire causes the magnetic lines due to the magnetic field to move closer together, which in turn increases the strength of the magnetic field. The greater the number of loops or coils, the stronger the magnetic field.
What is electromagnetic induction?
Electromagnetic induction is the production of an induced current and an induced voltage in a wire due to a changing magnetic field made by moving a magnet in and out of a coil of the wire. If a large resistance is present in the circuit or wire coil, voltage could still be induced, but current would not be induced in the wire due to the large resistance.
How is current affected by electromagnetic induction?
When a magnetic field is moved in one direction relative to a stationary coil, the current produced moves in one direction in the wire of the coil. When the magnetic field is moved in the opposite direction relative to the coil, the current in the wire flows in the opposite direction.
What affects the voltage produced via electromagnetic induction?
The voltage produced depends on the speed of magnetic field lines crossed by the wire. The faster the crossing of the lines, the greater the voltage. The greater the number of loops of wire that move in the magnetic field, the greater the current and induced voltage.
What is Faraday’s Law?
Faraday’s Law describes how induced voltage is related to the rate of change of a magnetic field relative to a wire. The law states that the induced voltage in a wire is directly proportional to the product of the number of loops, the cross-sectional area of each loop, and how fast the magnetic field changes within the coil.
What is a generator?
A generator is a device that changes mechanical energy into electrical energy. Since the induced voltage changes direction when the magnet is moved in versus out of the wire coil, the current produced by a generator is called alternating current (AC).
Here are some definitions to help you in your Grade 3-5 Lesson 1 investigation.
Magnet - any material that can make a magnetic field outside of itself
Magnetic Field - the space that shows the magnetic force around a magnet
Force - any push or pull on an object
Coil - wire formed into loops
Loops - a piece of wire formed into a circle
Electrical Energy - a type of kinetic energy made by moving electric charges
Kinetic Energy - energy due to the motion of an object
Conductor - a material that allows electricity to pass through the material
The lights suddenly go out and you’re alone in the dark. Can you make a working light using only a light bulb, piece of wire, and a bar magnet? If so, you’re ready for this challenge in electromagnetic induction.)
