Physical Science Chapter 10 Test
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
How does conventional current compare to electron current? Justify the use of the conventional current model.
Conventional current flows opposite the direction of electron flow. As the electrons flow through the conductor's positive charges appear to flow in the opposite direction. the flow of charges is still valid in both currents.
Series circuit
Has more than one electrical load connected one after another in a path or in a series. The current through each of the loads is the same for all loads in the series
What happens to the current in a short circuit? What can result from this?
In a short circuit the current is significantly increased due to load resistance created by the short. A fire could potentially result from a short circuit.
Parallel circuit
The current path splits two or more parallel paths through separate loads. The potential difference is the same across each load. The current is a function of potential difference and resistance
what is the unit of electrical current?
amp
what common electrical safety device is designed to prevent electrical fires? what newer device protects circuits specifically in bedrooms?
circuit breaker newer device- arc fault circuit interruptor
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, produced by chemically releasing electrons one time or over and over.
what device protects users from electrocution? how is the invention of such a device an example of dominion science?
ground fault circuit interrupter it was designed to protect humans who are made in God's image.
why can a person be shocked to death by less current than is required to start a fire?
heart muscle is sensitive to electrical current.
what is the unit of electrical power?
kilowatt-hour
what is the unit of electrical resistance?
ohm
give two reasons why circuit breakers are more effective and convenient than fuses.
reusable and quicker
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