Magnetism Flashcards
Explain how the poles of a magnet interact with each other.
Like poles repel.
Opposite poles attract.
Just like protons and electrons.
What is the name of the force that magnets exert on other magnets, iron or similar metal, or moving charges?
Magnetic Force
How does the magnetic force between objects change as the distance between the two objects is decreased.
The magnetic force increases.
Many other forces act the same way as the same amount of forceis spread out over a larger area.
What is the name of the area surrounding Earth that is influenced by the Earth’s magnetic field?
Magnetosphere
What is the name for a ferromagnetic material hat has domains that are aligned for a long period of time?
Permanent Magnet
As opposed to temporary magnets that constantly need to be remagnetized.
How can a permanent magnet be demagnetized?
Heat the magnet up.
Strike the magnet with a heavy blow.
What creates a magnetic field?
Moving electric charges.
Why is a soft iron usually used in the cores of electromagnets?
The are easily magnetized.
Electromagnets are commonly used in situations where the magnetic field needs to be “turned” on and off.
In an electric motor, periodically changing the direction in the electromagnet can cause the axle to spin because…
The magnetic field reverses direction.
The process of generating an electric current by moving an electrical conductor relative to a magnetic field is called?
Electromagnetic induction
A device that changes mechanical energy to electric energy by rotating a coil of wire through a magnetic field is called a…
Generator
How are fossil fuels used to generate electricity? (3 major steps)
Heat from burning fuel creates steam that spins a turbine (which is connected to a generator that makes electricity).
The generator spins 60 time per second, making our AC current.
What is a coil of wire that is carrying a current and producing a magnetic field called?
A solenoid.
What determines the strength of the output voltage and current of a transformer?
The number of turns in the primary and secondary coils.
What must be done to the voltage of generated electricity in order to efficiently transmit electrical energy over long distances?
A step-up transformer must be used to increase the voltage.
