Differences in materials used for production, methods of operating manufacturing equipment, and performance of workers cause products to differ from each other. What is the term for such differences? Differences in characteristics of two units of a product produced by the same company is referred to as .

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)