An insulating wall consists of 4cm of material of thermal conductivity `K_1` and a second layer of 8 cm thickness whose conductivity `K_2 = 4K_1` . The innermost and outermost surfaces are kept at `-10^@ C` and `76^@ C` respectively. Calculate the temperature at the interface.

Metal slab is made up of two parallel side plates of metal A and metal B of thickness 0.6 cm and 0.4 cm respectively. Their respective thermal conductivities are 2.268 and 1.008 SI unit. The outer surface of the plate A is at 220^@ and that of plate B at 20^@ . Find the temperature of the interface .

The conductivity of 0.20 M solution of KCl at 298 K is 0.248S cm^(-1) . Calculate its molar conductivity.

The enthalpy and entropy change for a chemical reaction are -2.5x 10^3 cal and 7.4 cal K^-1 respectively. Predict that nature of reaction at 298 K is:

Calculate the equivalent conductivity of 1M H_2 SO_4 solution if its specific conductivity is 26 xx 10^(-2) ohm^(-1) cm^(-1) .

Two rods 1 and 2 of same length have same temperature difference between their ends. Their thermal conductivities are K_1 and K_2 , and cross sectional areas A_1 and A_2 respectively. What is the required condition for the same rate of heat conduction in them ?

A pond is covered by a sheet of ice 2.0 cm thick (thermal conductivity 1.6 jm^(-1)s^(-1)k^(-1) . The temperature of the lower surface of ice is 0^@ C and that of the upper surface is -10^@ C . At what rate is heat conducted through each square meter of the ice ? What is the direction of this flow of energy ?

The resistance of a metallic wire is 10Omega at 9^@C . Calculate its resistance at a temperature of 100^@C . Gien a = 3.9 xx 10^-3 K^-1