What's the ampacity of a no. 10 tw copper wire in a raceway containing six wires and located in a area where the ambient temperature is 50°c?
a. 13.9 a
b. 8.6 a
c. 15.1 a
d. 10.8 a

Amixture of slurry and mud is to be pumped through a horizontal pipe of diameter 500 mm. the fluid behaves as a bingham plastic with a yield stress of 30 pa and viscosity 0.04 pa.s. describe the effects of the shear stress through a transverse section of the pipe by plotting the variation in shear stress and velocity profile: (i) just before the slurry starts to move (ii) as the slurry flows when the pressure gradient is double that in part (i)