Download Electricity - Current



Electric current: The continuous flow
of electrical charges through a
material.
The unit that measures the rate of
the current (the flow rate) is the
ampere.
◦ This is shortened to “amps”.

The number of amps describes the
amount of charge flowing past a
given point.
 In
order to maintain an electrical
current the charge must flow in a
continuous loop.
 A complete, unbroken path that
charges flow is called a
________________.
◦CIRCUIT!!!!!
 Conductor:
a material through
which charges can flow easily.
◦ Ex. Metals
 Insulators:
a material that does
not allow charges to flow through.
◦ Ex. Rubber, wood
 Charges
flow because the
differences in electric potential
energy.
 Potential
energy from an energy
source can be converted into
other forms of energy
 Voltage:
The difference in
electrical potential energy
between two points on a circuit.
◦ This is measured in volts
 This
difference in energy causes
charges to flow.
 This
is the measure of how
difficult it is for charges to flow
through an object.
◦ The greater the resistance the less
current there is.
◦ Resistance is measured in Ohms.
 There
are 4 factors that determine
the resistance of an object.
◦ Diameter, length, material, temperature
 Diameter:
current flows more
easily through a wider diameter
wire.
 Length:
shorter wires provide less
resistance
 Material:
some materials have
electrons that are tightly held
together, because of this the
electrons don’t transfer well.
 Temperature:
resistance usually
increases as the temperature
increases.