Describe how the electrical resistance of a wire changes as the wire becomes longer. How does the resistance change as the wires becomes thicker?
The resistance of a perfect resistor is R pAl where p is a resistivity constant (unchanged for a specific kind of wire), A is the cross sectional area (related to the thickness) and l is the length. If you increase l, can you see what happens to R?
The resistance of a wire is directly proportional to length.
The formula for resistance is Rpl/A. So as the length of wire increases, the resistance also increases. As the wire becomes thicker then its area increases. Since the resistance is inversely proportional to area, its value gets reduced.
