Poles
A NORTH pole and a NORTH pole of 2 magnets will (attract/repel)?
Repel
How does a compass work?
Magnetized needle on free-rotating swivel that detects Earth's natural magnetic field.
T/F: the poles of electromagnets can be flipped
True! If the current is reversed, so is the magnetic field, and the poles flip (north becomes south and south becomes north)
Positively charged particles are _____________
Negatively charged particles are ____________
Protons; electrons
When Hans Christian Oersted reversed the current direction traveling through his wire, what did the compass needle do?
Flipped around, because reversal of current also reverses the magnetic field produced by the current-carrying wire!!
Because magnets have TWO poles, they are called
Dipoles
What is one way to weaken a magnet?
Bang it against a table, heat it to a very high temperature
How would you turn an electromagnet off?
Cut off current flow, or detach from battery/ electricity source.
Which particle is responsible for the magnetic properties of a material?
Electrons
Who discovered that the magnetic field around a current-carrying wire forms a CIRCLE?
Oersted
Is the magnetic field of a magnet strongest at the North pole, the South pole, or both poles?
Both poles
How do maglev trains eliminate friction?
Use magnets to propel and levitate above the track; no wheels rubbing against a track
How would you make a solenoid into an electromagnet?
Insert a ferromagnetic material into the coil of wire (and make sure the current is turned on)
What is the iron-based mineral that is found in lodestones and makes them magnetic?
Magnetite
Which scientist discovered that electricity can be generated from magnetism?
Faraday
Where are magnetic field lines around a bar magnet most abundant/ concentrated?
Each pole
Give 2 examples of renewable (environmentally-friendly) energy sources
solar, wind, hydroelectric, geothermal
T/F: The magnetic field lines drawn around a solenoid would look the SAME as those drawn around a bar magnet.
True!
Define domains
Groups of individual atoms that form small, magnetized regions within a material.
Who discovered electromagnetic induction?
BONUS: provide a definition for an extra 100 points.
Michael Faraday
Electromagnetic induction= electric current produced by changing magnetic field
Where is the south pole of "Earth's magnet" located?
Northern hemisphere, somewhere around Northern Canada
Name TWO ways that maglev trains can provide a more environmentally-friendly way of travel.
No engine (no fossil fuel emissions), public transportation (less cars on road), also less noise pollution
Name TWO differences and ONE similarity between electromagnets and permanent magnets.
Differences: turned on and off, changing polarity depending on direction of current
Similarities: produce magnetic field, have 2 poles, attract ferromagnetic materials, etc.
Give an example of a material in which electrons are in pairs and are spinning in opposite directions.
anything that is NOT magnetic (i.e. wood, plastic, rubber, etc.)
Describe what Han's Christian Oersted did to discover the relationship between electricity and magnetism.
Put a compass next to a wire and observed that once a current was flowing through the wire, the compass needle deflected to align in a circle around the wire, showing that a circular magnetic field was being produced.