Bissoy.com
Doctors Medicines MCQs Q&A

As the temperature of a material is lowered, the yield stress _____ and the fracture stress _____

As the temperature of a material is lowered, the yield stress _____ and the fracture stress _____ Correct Answer Increases, decreases

Lower temperature retards dislocation mobility thus increases yield stress. Fracture stress of material decreases because the mobility of atoms decreases. Hence the tendency of brittle fracture increases.

Related Questions

If the specimen is deformed plastically beyond the yield stress in one direction, e.g., tension and then after unloading it is loaded in the opposite direction, e.g., compression, it is found that the yield stress is less than the original yield stress. This dependence of yield stress on direction loading is called ____________
Identify the correct statements from the following:
P. 0.2% yield strength of a material implies 0.2% of the yield strength.
Q. Von-Misses yield criterion implies that yielding occurs when the distortion energy reaches a critical value.
R. Radius of the cylinderical Von-Misses yield surface increases as the grain, size of a single phase material decreases.
S. Tresca's yield criterion gives a circular cylinderical surface in the space of the three principal stresses.
Consider the following statements for ductile fracture: 1. The material undergoes substantial plastic deformation with high energy absorption before fracture. 2. Presence of cracks on the surface of material initiates this type of failure. 3. Fracture occurs due to necking. Which of the above statements is/are correct? 
According to the fracture theory of the material, the critical value of the crack extension force, which makes the crack propagate to the fracture is called the fracture toughness of the material.
Fracture stress for a brittle material having a crack lenght of 1μm is 200 MPa. Fracture stress for the same material having a crack lenght of 4 μm is
At higher temperature, if higher frequency of stress cycle is applied on the material, fracture will be ___________ and at lower frequency of stress, the fracture will be ___________
Tresca or maximum-shear stress criteria assumes that yielding occurs when the maximum shear stress reaches a value of the shear stress in the uniaxial tension test. Assume the principal stress being σ1, σ2, σ3 where σ1 is largest, and σ3 is the smallest principal stresses. Find the value of minimum shear stress to cause yielding, given that yield stress in tension is equal to σo?
P, Q, R, Sand T are five crops that Babu grows. T is fast growing and more water demanding than R which gives more yield than T. P gives more yield than R and grows faster than Q. Q is more water demanding than T but is second lowest yielder, S is the slowest growing and least water demanding of all crops but gives highest yield. R is more water demanding and grows faster than P. Select the crop or crops that has/ have as many as crops that are more water demanding and as many as crops that give less yield than it. 
Examine the following statements :
i) Factor of safety for steel should be based on its yield stress,
ii) Factor of safety for steel should be based on its ultimate stress,
iii) Factor of safety for concrete should be based on its yield stress,
iv) Factor of safety for concrete should be based on its ultimate stress.
The correct statements are
Elastic failure of a material occurs, when the tensile stress equals yield strength, yield point or the elastic limit. Also, the elastic failure occurs according to maximum strain theory, when the maximum tensile strain equals (where, σ = yield strength and E = modulus of elasticity)