Question
Two wire of equal lengths, one of copper and the other of manganin have the same resistance. Which wire is thicker?
Solution
Resistance is given by R=
The length and resistance of the wires are equal.
Resistivity of Copper wire is less than that of the resistivity of magnanin wire. Therefore, the area of cross- section of copper wire is less than that of magnanin.
Hence, Manganin wire is thicker.