Discuss the below in detail:
Q: To determine air velocity changes, it is proposed to measure the electric current required to maintain a platinum wire of 0.5-mm diameter at a constant temperature of 77°C in a stream of air at 27°C.
(a) Assuming Reynolds numbers in the range 40 < red="">< 1000,="" develop="" a="" relationship="" between="" the="" wire="" current="" and="" the="" velocity="" of="" the="" air="" that="" is="" in="" cross="" flow="" over="" the="" wire.="" use="" this="" result="" to="" establish="" a="" relation="" between="" fractional="" changes="" in="" the="" current,="" ?i/i,="" and="" the="" air="" velocity,="" ?v/v.="">
(b) Calculate the current required when the air velocity is 10 m/s and the electrical resistivity of the platinum wire is 17.1 x 10-5 n · m.