The value of Biot number is very small (less than $$0.1$$), when

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