Three metal rods of same lenghs and same area of cross sections having conductivities `1,2,3,` units are connected in series Then their effective conductivity will be .

Three metal rods of same lengths and same area of eross-section having conductivities 1,2,3 units are connected in series. Then theireffective conductivity will be

Three metal rods of same lengths and same area of cross-section having conductivities 1, 2, 3 units are connected in series. Then their their effective conductivity will be

Three rods of same length and area of cross-section but of thermal conductivities K, 2K and 3K are connected in series in the same order. Free end of the first rod is at 0^(@)C and free end of third rod is at 55^(@)C . In steady state, temperature difference across the middle rod 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 metallic rods are connected in series. Both are of same material of same length and same area of cross-section. If the conductivity of each rod be k, then what will be the conductivity of the combination ?

Two conductors of identical dimensions of length and area of cross section are connected in series. What will be their equivalent thermal conductivity?

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