1.What is the major heat transfer mechanism in a heat pipe? Name the major operation limits of a heat pipe. 2. A heat pipe with copper shell, copper wick and water as the working fluid is transferring 100 W thermal power at steady-state operating conditions. The heat pipe dimensions are as follows: evaporator length = 0.1 m, condenser length = 0.1 m, adiabatic section length = 0.1 m, and an outer diameter of 0.01 m. The average evaporator and condenser section temperatures of the heat pipe are measured as 105 °C and 95 °C, respectively. Calculate (a) the thermal resistance of the HP, and (b) the effective thermal conductivity of the heat pipe. 3.If a copper rod with a length equal to the effective heat transfer length of the heat pipe in Problem 2 (Leff = 0.5 Le + La + 0.5 Lc) was to be used to transfer 100 W with the same temperature difference as defined in Problem 2, what would be the cross-sectional area needed for the rod? Compare the diameters of the rod and the heat pipe. You will use Fourier’s Law and assume a linear temperature distribution.