Question

Two wires, one of copper and the other of manganin, have same resistance and equal thickness. which wire is longer ? justify your answer. (1)

Answer 1

copper wire is longer as it has a low resistivity.

R= rho*l/A
rho=A*R/l

from above, l is inversely proportional to resistivity. as copper less resistivity than Manganin so it must be longer than Manganin according to above situation