Two wires of equal length, one of copper and the other of manganin have the same resistance .Which wire is thicker ?

Explanation

`R=rho 1/A`
Here, R and l are both equal for the copper and manganin wires.
`R=rho_1 1/A_1=rho_2 1/A_2or,A_1/A_2=rho_1/rho_2`
Resistivity of copper `(rho_1)` is less than `(rho_2)` of manganin.
`therefore A_1 lt A_2` i.e., the area of cross section of the manganin wire `(A_2)` is greater.SO the manganin wire is thicker.