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 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

Three metal rods of same length and same cross - sectional area are connected in parallel. If their conductivities area 70, 110, 180 Wm^(-1) K^(-1) respectively, the effective conductivity (in Wm^(-1) K^(-1)) of the combination is

The metal rods of same length and same area of cross-section are connected in series. If their condcutivites are 120 Wm^(-1) and 240 Wm^(-1) K^(-1) the effective conductivity of the combination is

Two identical metal wires of thermal conductivities K_(1) and K_(2) respectively are connected in series. The effective thermal conductivity of the combination is :

Electrical conductivies of Ge and Na are sigma_(1) and sigma_(2) respectively. If these substances are heard, then

Two identical metallic wires are connected one after other. Find their K_eq

A metal wire of length L_1 and area of cross-section A is attached to a rigid support. Another metal wire of length L_2 and of the same cross-sectional area is attached to free end of the first wire. A body of mass M is then suspended from the free end of the second wire. If Y_1 and Y_2 are the Young's moduli of the wires respectively, the effective force constant of the system of two wire is