Air at 403 K and 1 atm enters a convergent nozzle at a velocity of 150 m/s and expands isentropically to an exit pressure of 76 kPa. If the inlet area of nozzle is 5x10-3 m2
, find (a) stagnation temperature, pressure and enthalpy, (b) inlet Mach
number (c) exit temperature, pressure, Mach number and area, (d) what must be the
back pressure, temperature, and flow rate if sonic conditions are attained at exit.
Assume air to be perfect gas.

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk

Ahot wire operates at a temperature of 200°c while the air temperature is 20°c. the hot wire element is a tungsten wire of 5 um diameter and 2 mm in length. plot using excel current, heat transfer and heat generated by the wire for air velocity varying from 1-10 m/s in steps of lm/s? matlab the sensor voltage output, resistance, or assume nu 0.989 re033pr13 take air properties at tr (200°c20°c)/2 = 110°c properties of tungsten: c 0.13 kj/kg.k 3 p 19250 kg/m k (thermal conductivity) = 174 w/m.k