E & EM
What are two types of electric charges
positive and negative
Name some ferromagnetic materials
Iron, nickel, cobalt
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.
Glass, rubber, and wood
What is magnetosphere?
Earth's magnetic field is called magnetosphere.
What happens when compass is put close to a magnet?
The north pole of compass will point to the south pole of the magnet.
Identify the parts of a generator.
power source, rotating coil, magnet.
Where is the magnetic force the strongest?
At the magnetic poles
WHAT ARE SOME EXAMPLES OF GOOD CONDUCTORS?
Silver, Sea water, Iron, copper
What is magnetic potential energy?
The energy of an object that has the ability to do work because of its position in a magnetic field is called magnetic potential energy.
Define 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 kind of metals are attracted to magnets?
Ferromagnetic metals or any metal with iron in it.
Natural magnetic material
Lodestone or Magnetite
What are some devices that involve/ contain electromagnets?
Electric motors, generators, door bell, transformers
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 is the difference between step up and step down transformer?
Step up- changes lower voltage to higher voltage.
Step down- changes higher voltage to lower voltage.
Can two south poles attract each-other? why?
No, they repel each other. Because like charges poles repel each other.
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 electromagnetic induction?
It is the process of generating current from a magnetic field.
Describe what happens when a charged object is brought near a neutral object
The presence of a charged object near a neutral conductor will force (or induce) electrons within the conductor to move. The movement of electrons leaves an imbalance of charge on opposite sides of the neutral conductor.
What is Faraday's law of induction?
By changing magnetic field can cause current to flow in wires.
What kind of magnets can be turned on and off?
Electromagnets.
What happens when a bar magnet is cut in half?
It makes 2 new smaller bar magnets with south and north pole on each.
How do you increase the power of a magnetic field?
- by using a powerful magnet
- by decreasing the distance between the magnet and the object.
Identify variables that will change the strength of electromagnets.