Resistivity

What is resisitivity?

A property that describes the extent to which a material opposes the flow of electric current through it.

What is the resistance equation regarding resistivity?

Resistance= resistivity * Length/ Cross sectional area R=ρL/A

What is the unit for resistivity?

Ohm metres (Ωm)

What is the resistance equation regarding resistivity, rearranged with resistivity as the focus?

Resistivity= resistance*cross sectional area/ length ρ=RA/L

What is the relationship between resistance and length?

Resistance is proportional to length.

What is the relationship between resistance and cross sectional area?

Resistance is proportional to 1/cross sectional area

What is the relationship betweeen resistance, length and cross sectional area?

resistance is proportional to length/cross sectioal area

What does the resistivity equation show?

The longer the wire the greater its resistance, the thicker the wire the smaller its resistance.

How are resistance and resistivity related?

The higher the resistivity of a material the higher its resistance.

Why is copper used for elctrical wires?

It has a relatively low resistivity at room temperature so current flows through it very easily.

What resistivity do insulator have?

A very high one so virtually no current will flow through them.

For a metallic conductor that obeys Ohm's law what do changes in temperature do?

An increase in temperature causes an increase in resistance, a decrease in temperature causes a decrease in resistance.