A hot-wire anemometer consists of a 5-mm-long, 5-mdiameter platinum wire. The probe is operated at a constant current of 0.03 A. The electrical resistivity of platinum is 17 cm at 20°C and increases by 0.385% per °C.
(a) If the voltage across the wire is 1.75 V, determine the velocity of the air flowing across it and the wire temperature if the free-stream air temperature is 20°C.
(b) What are the wire temperature and voltage if the air velocity is 10 m/s? Neglect radiation and conduction heat transfer from the wire.