Q. Two adiabatic vessels, each containing the same mass of water but at different temperatures, are connected by a rod of length , cross-section , and thermal conductivity . the ends of the rod are inserted into the vessels, while the rest of the rod is insulated so that there is negligible loss of heat into the atmosphere. The specific heat capacity of water is , while that of the rod is negligible. The temperature difference between the two vessels reduces to of its original value after a time, . The thermal conductivity of the rod may be expressed by :

Thermal Properties of Matter Report Error

Solution:

Suppose that the temperature of the water in the first vessel is and that of the second is , then
...(1)
and ...(2)
from (1) and (2), we get

where
The time, in which the temperature difference reduces to of its initial value, is given by