Download Current, Voltage and Resistance File

Name: _____________________
Current, Voltage
and Resistance
Atoms have a __________ nucleus with ____________ electrons orbiting around it.
Current
Electric current is nothing more than the flow of ______________________ of electrons
through a wire or conductive material.
For example, if you connect a piece of wire between the positive and negative terminals
of a charged battery, electrons from the _______________ side will flow through the
wire to the _____________________ side of the battery.
On the negative side of a charged battery there are millions and millions of electrons that
___________________ from their atoms through a chemical reaction and accumulated
on the negative side.
On the positive side of the battery there are millions and millions of atoms that
_____________ electrons and therefore they lost their neutrality and have a
_____________ charge. The electrons, attracted by the positive ____________, travel
through the wire from the negative side of the battery to the positive side, this flow of
electrons constitutes an ____________________________________.
The amount of current that flows through a wire is measured in ______________, also
called Amps. The Ampere indicates how many electrons ___________ through the wire
per _____________________.
A current of 1 Ampere constitutes 6.24 E18 (6.24 x 10____) electrons flowing per second
through the wire or 6,240,000,000,000,000,000 (6 quintillion two hundred forty
quadrillion).
Voltage
Voltage is the force or the _____________________ that causes the current to flow
through a wire or conductive material. The voltage is produced by the accumulation of
___________________ and ___________________ charges on the terminals or poles of
a battery or electric generator.
This difference of __________________________________________ across the
terminals of a battery will cause an electric current to flow through a wire or conductor
connected across the terminals.
Resistance
Resistance is the _________________________ that materials present to the flow of
current (opposition to current flow).
According to their resistance, materials can be classified into _________________,
_______________________ or ________________________.
Some materials like copper, aluminum, gold and other metals have the ability of allowing
electrons to flow through them. They are good conductors of electricity because some of
the electrons from their atoms left the __________________ and became free to wander
from atom to atom through the __________________________.
This movement of free electrons in a conductor does not produce an electric current
because it is erratic (in any direction) and not in a specific direction which occurs when a
voltage is applied across the conductor.
When voltage is ________________ across a ______________________ all the free
electrons start moving toward the ______________________ side of the voltage source.
This movement of free electrons in one specific direction constitutes an
____________________.
Insulators
There are some materials that ___________________________ free electrons wandering
from atom to atom in their atomic structure. This means that each electron is on its
respective orbit and not going from one atom to another. Materials with these
characteristics like ___________________________________________ do not allow
electric current to flow through them. They are called insulators.
There are materials such as silicon and germanium that are neither good conductors or
good insulators of electricity. They are between these two categories and are called
________________________________. As you will learn in future courses
semiconductors perform a very important role in electronics, as we have said earlier they
are used to manufacture ________________________________________________, etc.
Resistance
Good conductors of electricity such as copper, aluminum and gold have a very low
_____________________. Insulators, such as glass, porcelain and rubber have a very
__________________________resistance. Semiconductors have a medium resistance,
neither high or low.
Resistance is measured in ____________________. A short piece of copper wire has
less than 1 ____________ of resistance on the other hand a short piece of glass might
have a resistance in millions of ohms.
There are certain types of electronic components called resistors which are used to
_______________________________ in circuits. Each resistor has a specific resistance.
The value of resistance of each resistor is specified with marks on its case using
_______________________________________