Two identical plates with thermal conductivities K and 3K are joined together to form a single plate of double thickness. The equivalent thermal conductivity of one composite plate so formed for the flow of heat through its thickness is.

If two metallic plates of equal thickness and thermal conductivities K_1 and K_2 ​are put together face to face and a common plate is constructed, then the equivalent thermal conductivity of this plate will be

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

IF two metallic plates of equal thickness and thermal conductivities K_(1) and K_(2) are put together face to face anda common plate is constructed, then the equivalent thermal conductivity of this plate will be

If two metallic plates of equal thickness and thermal conductivities K_(1) and K_(2) are put together face to face and a common plate is constructed, then the equivalent thermal conductivity of this plate will be

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 thick plate is constructed by two plates of equal width with thermal conductivities k_1 and k_2 . What will-be its equivalent thermal conductivity?

Two identical plates of different metals are joined to form a single plate whose thickness is double the thickness of each plate. If the coefficients of conductivity of each plate are 2 and 3 respectively, Then the conductivity of composite plate will be