Two metal wires of identical dimesnios are connected in series. If `sigma_(1)` and `sigma_(2)` are the conducties of the metal wires respectively, the effective conductivity of the combination is

Two metal wires of identical dimensions are connected in series. If sigma_(1) and sigma_(2) are the conductivities of the metal wires respectively, the effective conductivity of the combination is

Two metal wires of identical dimensions are connected in series. If sigma_(1) and sigma_(2) are the conductivities of the metal wires respectively, the effective conductivity of the combination is

Two metal wires of identical dimensions are connected in series if sigma_(1) and sigma_(2) are the conductivity of the metal wire respectively the effiective conductivity of the combination is

Two metal wires of idential dimensions are connected in series. If sigma_(1) and sigma_(2) are the conductivities of the metals respectively, the effective conductivity of the combination is

Two metal wires of identical dimensions are connected in series. If sigma_1 and sigma_2 are the electrical conductivities of the metal wires respectively, the effective conductivity of the combination is

Two metal wires of identical dimensions are connected in parallel.If "rho_(1)" and "rho_(2)" are the resistivities of the metal wire respectively,the effective resistivity of the combination will be

sigma_(1) and sigma_(2) are the electrical conductivities of Ge and Na respectively. If these substances are heated, then

A copper wire and an iron wire, each having an area of cross-section A and lengths L_(1) and L_(2) are joined end to end. The copper end is maintained at a potential V_(1) and the iron end at a lower potential V_(2) . If sigma_(1) and sigma_(2) are the conductivities of copper and iron respectively, then the potential of the junction will be