behave is dictated by the relationship specified Electric conductor
by Ohm’s law
The conductance is the property of some
V= I R. It states that the voltage (V) across a materials to let the electric current to pass freely
resistor is proportional to the current (I), the throughout these materials, and is determined
resistance is measured in units of ohms (Ω). by; G = σ(L/A) where L is the length of the
Figure 5 and 6 show the symbols used to conductor, measured in meters [m], A is the
identify the resistors.
cross-section area of the conductor measured in
square meters [m²], σ (sigma) is the electrical
conductivity measured in Siemens per meter
(S•m−1).
The
metals
are
good
electrical
conductors because they do not have too much
opposition to the electric current flows, copper
conductor material is one of the better known,
the
electrical
conductivity
of
a
conductor
depends of 1) The intrinsic parameter σ, the
bigger its value, the better is its property to
Fig 5
Fig 6
conduct the electric current. 2) The conductor´s
cross section area, the bigger the area, less
Figure 7 shows a resistor of 10 (Ω), an opposition to the electric current flows. 3) The
electric
current
of
1
ampere
is
flowing conductor´s length, the shorter the length, the
throughout, which according the ohm´s equation bigger the conductance and vice-versa, for
this
electric
current
provokes
a
voltage technical practical purposes the opposition to
difference of 10V between the resistor terminals. the electric current of a short length copper
electric conductor wire is not taking into account,
but when an copper electric conductor is too
long, and at the same time it conveys too much
electric current, it opposes in some degree to
Fig 7