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

Explanation

`R_("copper")= rho_(c) (1_(c))/(A_(c))`
`R_(m)= rho_(m)(l_(m))/(A_(m))`
Now `" " R_(c) = R_(m) ` ( given )
`l_(c)=l_(m) ` (given )
`:. (rho_(m))/(A_(c))=(rho_(m))/(A_(m))`
or `" " (rho_(c))/(rho_(m))=(A_(c))/(A_(m))`
Since `" " rho_(m) lt rho_(c)`
`:. " " A_(m) lt A_(c)`
Copper wire will be thicker .