Resistance and Resistivity
Directions:
TYPE ALL of YOUR ANSWERS IN A
DIFFERENT COLOR
(not black!)
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Objectives:
1. To study the relationship between the resistance of a wire and its dimensions
2. To know the effect of the type of material on its resistance.
3. To distinguish between resistance and resistivity
4. To find the resistivity of a given wire and from this determine the material
Apparatus:
Theory:
Resistivity (ρ) is a fundamental material property, while the resistance (R) of an electrical
conducting wire depends on several factors, such as: type of conductor material, length of
the conductor, cross-sectional area, and the temperature of the wire.
At a constant temperature, the resistance R of a given conductor is directly proportional
to its length L and inversely proportional to its cross-sectional area A.
This resistance is given by the following formula:
Where:
ρ:
is the resistivity of the wire material measured by (Ω.m)