Ch. 7 Sec.1 -3 Flashcards
Magnetism
A physical phenomenon produced by the motion of electric charge, resulting in attractive and repulsive forces between objects
Refers to the properties and interactions by magnets
Ex. Like repel, opposite attract
Magnetic field
A region around a magnetic material or a moving electric charge with in which the force of magnetism acts
Region of space that surrounds a magnet and exerts a force on another magnet and objects made of magnet material
Ex. All the line connecting north to south
Magnetic poles
Each of the two points or regions of an artificial or natural magnet to and from which the lines of magnetic force are directed
Regions of a magnet that exert the strongest force
Ex. North and south
Field lines
A line used to indicate the direction of the field, especially on electric or magnetic field, at various points in space
Represented by force lines
Ex. The way iron fillings would move if close to a magnet
Magnetic domain
A region in which the magnetic fields of atoms are grouped together and aligned
Group of atoms with aligned magnetic poles
Ex. < > ^
Why are some objects magnetic in others aren’t?
The magnetic fields of these electrons are canceled out by another, oppositely oriented, electron. As such they lend an overall magnetic field to the atom they inhabit. So, some metals are attracted to magnets because they are full of tinier magnets
Permanent Magnet
A magnet that retains its magnetic properties in the absence of an inducing field or current
Field is strong enough to keep the atoms aligned
Ex. Iron alloy
Electromagnetic Force
Surprise attractive or repulsive forces between electric charges and current
Fundamental force a nature, electromagnetic force acts between two charged particles and is the combination of all electrical and magnetic forces.
Ex. Forming atoms and molecules
Electromagnetism
Interaction between electric charges and magnets
Electric charges and magnetic fields collide
Ex. EMF
Solenoid
Single wire wrapped in a shape of a cylinder
Single coil of wire acting as a magnet when carrying electric current
Ex. Cars starting system
Electromagnet
A temporary magnet created when there is a current in a wire coil
A soft metal core made into a magnet by the passage of electric current through a coil surrounding it
Ex. Speakers
Galvanometer
Device that uses an electromagnet to measure electric current
Instrument for detecting and measuring small electric currents
Ex. Affected like to coils in a small magnet
Uses of electromagnets
Strength - increase current and increase more turns in solenoid
on and off
Electric motors
Device that changes electrical energy into mechanical energy
Electrical machine that converts electrical energy into mechanical energy
Ex. Blender
Electromagnetic induction
Generation an electric current by a changing magnetic field
Process work and doctors placed a changing magnetic field
Ex. Generates energy we use
Generator
Uses electromagnetic induction to transform mechanical energy into electrical energy
Similar machine for converting mechanical energy to electricity
Ex. Cool rotates between poles of a permanent magnet
Turbine
Connected to a rotating magnetic generator
A machine for producing continuous power in which a wheel or rotor, typically fitted with vanes is made to revolve by fast moving flow water, steam, gas, air, or other fluid
Ex. Wind/ water turbine
AC/DC
A/C: is something plugged into the wall
D/C: battery
A/C: most electric power is a sine wave
D/C: The unidirectional flow of electric charge
Ex. A/C: toaster
D/C: battery
Transformers
A device that increases and decreases the voltage of an alternating current
An apparatus for reducing or increasing the voltage of an alternating current
Ex. Step-up
Step-down
V out = N 2
V in N 1
Output voltage = secondary
Input voltage primary
