Physical Science Chapter 10 C
name four man made sources of electrons that could produce an electrical current. which recycle electrons.
1) dry cell batteries 2) wet cell batteries 3) photovoltaic cells 4) mechanical generators photovoltaic and mechanical generators recycle electrons.
what are the minimum components needed for an electrical circuit to do useful work? what device allows us to control whether or not current flows in a circuit?
1) source of electrons 2) electrical load 3) conductors controlled by a switch
what is the unit of electrical current?
ampere or amp
a portable cd player uses aa 1.5 battery. when running, the player uses 57 ma (o.057A) of current. How much does electrical resistance does the cd player have?
battery voltage (v)=0.057 A ; unknown
how does conventional current compare to electron current? justify the use of the conventional current model.
conventional current flow is opposite of the dirrection of electron flow. for every electron that moves in one direction there is a positive charge left behind.
compare the two models of how electrons flow through a conductor.
diffusion model: higher concentrations of electrons move toward lower concentrations of electrons. electrical potential model: electrons at source have higher potential energy and tend to flow toward points of lower potential energy.
what is the name for current that flows in one direction? in what two ways can this kind of current be produced?
direct current flows in just one direction. it can be produced by chemically releasing electrons to do work one time only,, (as in batteries)
the unit of electrical power is the kilowatt-hour
false the kilowatt-hour is a unit of energy. electrical power is measured in watts
what is the unit of electrical resistance?
ohm
contrast static electricity and current electricity.
static electricity: stationary electrical charges. current electricity: continuously flowing electrical charges.
what is the unit for electrical potential difference?
volt