Physics Electric Current
what is parallel circuit
a circuit with more than one path for current to flow, current divides up to flow through parts, one goes the other stay
what is a series circuit
a circuit with only one path for current to flow, current moves flow through every part, if one part goes out the whole circuit goes
what happens to lights in a series circuit is one light burns out
all lights turn off
what happens to lights in a parallel circuit if one light burns out
all stay at the same brightness
what is AC circuit
alternating current and is produced by power company and is generated by a generator
how do electrons move in an alternating current circuit
back and forth
what provides the "force" or "push" to move charges in a circuit
battery (potential difference)
what are four ways that you can increase resistance in a wire
change the material to less of a conductor length- longer wires have more resistance size- smaller (narrower) wires have more resistance temp- higher temp have more resistance
in a series circuit what value is constant across all resistors
current (I)
what is DC circuit
direct circuit and flows in one direction and is produced by a battery
kilowatt hour is a measure of what
energy
state Ohm's law
equation that gives the relationship between voltage, current, and resistance V=IR; potential difference is equal to the product of the current and the resistance.
3 examples of common used things that use DC
flashlight, toy car, remote
how do electrons move in a direct current circuit
from positive terminal to negative terminal
alternating current is made by what types of devices
generator
3 examples of common used things that use AC
hair dyer, iron, toaster
in order for current to exist in a circuit, what criteria must be met
it must be a closed path or conducting material (wire) and have a battery that supplies a potential difference
what are three ways you can change the resistance of a wire
length- longer wires have more resistance size- smaller (narrower) wires have more resistance temp- higher temp have more resistance
what is an ammeter and what does it measure
meter that measures current; it is wired in series
resistance
restraint in the flow of charge, ohms
current
the flow of electrons from one place to another (amps)
voltage
the potential difference across a circuit that causes current to flow (electrical pressure) Volts
define electrical power and give its unit
the rate at which energy is used by a circuit (watt)
power
the rate at which energy is used by a circuit, watts (w)
what is the purpose of fuses and circuit breakers in a circuit
these are used to protect the circuit from to much current. they stop the flow of current before reaching equipment
as current flow in a circuit increases what happens to resistance and voltage
voltage increases and resistance decreases; but this doesn't happen spontaneously
in a parallel circuit what value is constant across all resistors
voltage(V)
if there are four resistors wired in series, how may circuit pathways exist
1
if there are 4 resistors wired in parallel, how many circuit pathways exist
4