Two rods of the same length and diameter, having thermal conductivities `K_(1)` and `K_(2)`, are joined in parallel. The equivalent thermal conductivity to the combinationk is

Two rods of equal length and diameter but of thermal conductivities 2 and 3 unites respectively are joined in parallel. The thermal conductivity of the combination is:

A slab consists of two layers of different materials of the same thickness and having thermal conductivities K_(1) and K_(2) . The equivalent thermal conductivity of the slab is

A slab consists of two layers of different materials of the same thickness and having thermal conductivities K_(1) and K_(2) . The equivalent thermal conductivity of the slab 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 :

A slab consists of two parallel layers of two different materials of same thickness having thermal conductivities K_(1) and K_(2) . The equivalent conductivity of the combination is

Two rods of equal length and diameter have thermal conductivities 3 and 4 units respectively. If they are joined in series, the thermal conductivity of the combination would be:

Two rods of equal length and diameter have thermal conductivities 3 & 4 units .it they joined in series . Find the thermal conductivity of the combination.