Question

Two wires,one of manganim and the other of copper have equal lengths and resistance.which one of the these wires will be thicker?​

Answer 1

Manganin is thicker

Explanation:

Resistance R of a wire of length l and cross sectional area A (thickness) is given by ,

          R=ρl/A

where ρ= specific resistance of wire

for copper wire      R=ρcl/Ac ,

for manganin wire  R=ρml/Am

or                          ρc/Ac=ρm/Am

or                          Ac/Am=ρc/ρm

we know  ρm>ρc  (as manganin is an alloy)

therefore               Ac<Am

Hence manganin wire is thicker.