The properties of mercury at $$300K$$ are : density $$ = 13529kg/{m^3},$$ $${C_P} = 0.1393$$ $$kJ/kgK,$$ dynimic viscosity $$ = 0.1523\,\, \times \,\,{10^{ - 2}}\,\,N - s/{m^2}$$ and thermal conductivity $$=8.540$$ $$W/m$$-$$K$$. The Prandtl number of the mercury at $$300K$$ is

What is the value of the view factor for two inclined flat plates having common edge of equal width, and with an angle of $$20$$ degrees?

For the same inlet and outlet temperatures of hot and cold fluids, the Log mean temperature Difference $$(LMTD)$$ is

An item can be purchased for Rs.$$100.$$ The ordering cost is Rs.$$200$$ and the inventory carrying cost is $$10\% $$ of the item cost per annum. If the annual demand is 4000 units, the economic order quantity (in units) is