Electricity and magnetism
Monthly project ideas
Earth as a magnet (poles, magnetic field)
Commercial magnets (tvs, speakers, junkyards, etc)
Permanent v. temporary magnets
Electromagnets
Electric circuits
Generators
Electric motors
Wind power
Water power
How electricity gets to your house
Power lines
Static electricity
Experiments involving electricity or magnetism
Charles Coulomb
Nikoli Tesla
Georg Ohm
Hans Christian Oersted
Circuit boards
House wiring
Batteries and how they work
Electricity in the body (brain, nerves)
Lightning
Monorails (train)
Study guide
Concepts:
series v. parallell wiring with diagrams
earth as a magnet
how a magnet is structured and what would happen if it broke
diagram and description of dry cell
how fuses work and different types of fuses
what to do if lights go out in your house
Vocabulary:
ohm
volts
circuit
open and closed circuit
magnetosphere
magnetic field
magnetic lines of force
load
amperes
circuit breaker
resistance
conductor/insulator
current
hot bus bar
switch
v=IR
conduit
temporary/permanent magnet
electric cell
w =va
Notes:
Electricity
electricity magnetism result of positive/negative charges
electric force - like repel, opposite attract
protons, electrons
electric charge measured in coulombs (c)
static electricity when charges transferred due to motion
current - flow of e-
amperes - measures current
miliamps - mA
Coulomb's Law - force between two charged particles related to number of charges and distance
electric potential - push given to electrons
measured in volts
closed circuit - complete path for e-
open circuit - break in path
conductors - object that lets electricity flow easily
insulator - object that does not let electricity flow easily
resistance - measurement of how difficult for e- move through object
measured in Ohms
Ohm's law - predicting the flow of amps
V(volts) = I(current) x R(resistance)
load - part of circuit uses electricity
circuit breaker - used to detect amount of heat and current - cuts off if excess
electric discharge - transfer of electric cahrges
electric cell (battery) - converts chemical energy to electric energy
terminals and electrolyte, dry cell and wet cell
direct current - flows in one direction
alternating current - current repeatedly changes direction
watts - energy per second
volts - potential difference, pressure causing current to flow
panel box - lever disconnect, pull out block, single main or multiple main
hot bus bar - divides current into smaller useable portions
parallel wiring - hot and neutral wires run one box to another
series wiring - hot wire passes through all lights before joining neutral wire
switch - open closes circuit
conduit - tubes carries wire
fuses - contains allow with low melting point
amp too great strip melts breaking circuit
edison base fuses - screws in 30 amps
type S - required in new installations 120 v
cartridge - ferrule - 10-60 amps, knife blade 70+ amps
Magnets
two sides called poles
force of attraction and repulsion
all magnets have north and south
earth is a large magnet
magnetoshpere - area surrounding earth
magnetic field - magnetic force surrounding magnet
magnetic lines of force - lines representing magnetic field
temporary magnet - easy to magnetize, easy to lose
permanent magnet - longer to magnetize, keeps longer
magnetic induction - process of magnetizing an object
Hans Christian Oerstad - 1800's
straight line of wire with current creates magnetic field
put wire into loops (solenoid) became like a bar magnet
more current, more loops - stronger field
created electromagnet
each atom has circulating e- so has its own magnetic field
generator - loop of wire placed in magnetic field - as coils rotates creates current
electric motor - electric energy into mechanical energy - uses current to create magnetic field
Electricity journal
Seven days
Keep track of major household appliance use - dryer, electric heat, oven, tv, lights
Read house meter each day at same time of day and record kilowatt hours