the buildup of electric charges on an object is called a _________ charge

static

two objects will attract one another when they have ___________ charges

opposite

one example of a good conductor is _______

copper

the steady flow of electrons through a conductor is an electric _____________

current

when the resistance in an electrical circuit increases, the current flowing in the circuit _________

decreases

resistance is measured in a unit called the ____

ohms

a path created for a current that allows only one route for the current is called a __________ current

series

a _________ breaker is a device designed to open an overload circuit and prevent overheating

circuit

electric companies usually sell electrical energy in units of ____

kWh

a circuit that has more than two or more separate paths for electrons to follow is a(n) ___________ circuit

parallel

the south pole of a magnet attracts the ______ pole of another magnet

north

when you break an iron magnet into two pieces, you get two ____________

magnets

the region around a magnet where the magnetic forces act is the ________________

magnetic field

the magnetic field of a magnet is strongest at the ________

poles

an electromagnet is only operating when the current is ___

on

the function of an electric motor is to change ____________ energy to _____________ energy

electrical; mechanical

a current carrying wire wrapped around an iron ore is called a(n) _______________

electromagnet

current that does NOT reverse direction is called _______________________

direct current

a simple complete circuit must have wires connected to a __________ and an ___________________

load; energy source

when you walk across a carpeted floor and then touch a metal doorknob, the "shock" you may feel occurs because of a(n) static _____________

discharge

when you rub a balloon on your hair, __________ go from your hair to the balloon

electrons

in a battery, electrons flow from the _________ terminal to the ___________ terminal

negative; positive

a wire that is long and _________ would have the greatest electrical resistance

thin

two identical balloons are both rubbed with wool. If the balloons are brought near each other, they will ________ each other

repel

the core of an electromagnet is usually made of ______

iron

a magnetic field exists around a wire whenever a ________ flows through the wire

current

earth's magnetic field is called the _________________

magnetosphere

List and describe the three essential parts of a circuit

1) wires- conducts current
2) energy source- supplies charge
3) load- uses electrical energy

describe how direct current differs from alternating current

direct currents- only travels in one direction
alternating currents- switches directions

how does lightning form?

1) charges build up in clouds
2) cloud charges are attracted to opposite charges on the ground
3) when imbalance of charges become too great, you get a discharge = lightning