E & EM
What are the 3 examples of ferromagnetic material?
Iron, cobalt, nickel
Magnetic force is a _____________ force.
Non-contact
How could you increase the strength of an electromagnet?
What poles attract in magnets?
Unlike poles attract in magnets.
Are the magnetic poles of Earth aligned with the geographical poles?
No, they are 10 degrees apart.
What are two types of magnets?
- Permanent magnets
- Temporary magnets
Where is the magnetic force the strongest on the magnet?
At the magnetic poles.
How do maglev trains use magnets?
The maglev trains use magnets to levitate on the track and pulled in forward direction.
What is an electric generator?
It converts kinetic energy into electrical energy.
What are the two kinds of transformers?
- Step up Transformer
- Step down transformer
What is an electromagnet?
Magnet created by passing an electric current.
How does an electric generator work using water?
It converts the kinetic energy of moving water into electrical energy.
What is induction?
Charging an object without touching it.
What is magnetic domain?
There are regions where the north and south poles of atoms are all lined up in the same direction in different materials. These regions are called magnetic domains.
What are the two types of forces exerted by magnets?
Forces of Repulsion and attraction
What does it mean if an object has a neutral charge?
If an object is neutral, that just means that it has an equal number of positively and negatively charged particles.
Explain how the Earth creates a magnetic field
On Earth, flowing of liquid metal in the outer core of the planet generates electric currents. The rotation of Earth on its axis causes these electric currents to form a magnetic field which extends around the planet.
What is the right hand rule?
When the thumb of the right hand is pointing in the same direction as the current(positive charge), the fingers of the right hand curl around the wire in the direction of the magnetic field.
What is a solenoid?
A solenoid is a coil of wire with electric current flowing through it, giving it north and south magnetic poles and a magnetic field.
What is Faraday's law of induction?
By changing magnetic field can cause current to flow in wires.
What happen when you cut a bar magnet in half?
The two small pieces act like magnets each with north and south pole.
What is an AC current?
Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time
What is static electricity?
A stationary electric charge, typically produced by friction, which causes sparks or crackling or the attraction of dust or hair.
What are electrical charges and how do they interact?
There are two types of electric charges- positively and negatively charged. Opposite charges attract and like charges repel.
What are some devices that involve/ contain electromagnets?
Electric motors, generators, door bell, transformers