This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
Which of the following type of flow occurs, when on applying critical shear stress, a material turns to liquid? 
Select and explain. 
A. Bingham body behaviour, B. Newtonian body, C. Dilatant, D. Pseudoplastic
A: Bingham body behaviour
Answer: A: Bingham body behaviour 
Explanation: The viscosity of many dental materials decreases with increasing strain rate until it reaches a nearly constant value. That is, the faster they are stirred, forced through a syringe, or squeezed, the less viscous and more fluid they become. This is pseudoplastic viscosity and is illustrated by the change in slope of the plot in the figure.
The viscosity of a pseudoplastic fluid decreases with increasing shear rate. 
The tomato-based food condiment ketchup is also pseudoplastic, which makes it difficult to remove from a bottle. Shaking the bottle or rapping the side of the bottle increases its shear rate, decreases its viscosity, and improves its pourability. 
 
A Bingham plastic is a viscoplastic material that behaves as a rigid body at low stresses but flows as a viscous fluid at high stress. It is named after Eugene C. Bingham who proposed its mathematical form.