1. What is the effect of Temperature on Viscosity in gas?
The viscosity increases due to momentum transfer. As temperature Increases, more molecules cross over with higher momentum differences. Hence, in gases viscosity increases with temperature.
2. What do you understand by Dislocations?
Dislocations are a line defect which occurs when a force is applied to a metallic material, move and cause a metallic material to deform.
3. What is Nitriding?
It is a process in which nitrogen is diffused into the surface of a material, such as steel, leading to increased hardness and wear resistance.
4. What is Notch sensitivity?
Notch sensitivity measures the effect of a notch, scratch, or other imperfection on a material’s properties, such as toughness or fatigue life.
5. What is True stress?
True stress is the ratio of the load divided by the instantaneous area over which the load acts.
6. What is Fatigue strength?
The stress required to cause failure by fatigue in a given number of cycles, such as 500 million cycles.
7. Name the important refractory metals?
The refractory metals include columbium (Cb), molybdenum (Mo), tantalum (Ta), and tungsten (W). Mo and W are the most important.
8. What is the defining characteristic of a Newtonian fluid?
A Newtonian fluid is one for which viscosity is a constant property at a given temperature. For ex- Most liquids like water, oils are Newtonian fluids.
9. What is a eutectic alloy?
A eutectic alloy is a particular composition in an alloy system for which the solidus and liquidus temperatures are equal. The temperature is called the eutectic temperature. Hence, solidification occurs at a single temperature, rather than over a temperature range.
10. What function is served by tempering?
Tempering involves heating and soaking of martensite for about one hour, followed by slow cooling to reduce brittleness, relieve stresses, and increase toughness and ductility.
11. Define hardenability?
Hardenability is the relative capacity of steel to be hardened by transformation to martensite.
12. What is fluid?
A fluid is defined as a material which will continue to deform with the application of shear force however
Small the force may be.
13. What is non-uniform flow of fluid?
If at a given instant, the velocity is not the same at every point the flow is non-uniform.
14. What is Load?
The force applied to a material during testing.
15. What is Modulus of resilience?
The maximum elastic energy absorbed by a material when a load is applied.
16. Define thermal diffusivity?
Thermal diffusivity is the thermal conductivity divided by the volumetric specific heat.
17. What are the two most common alloying metals used in solders?
Tin and lead.
18. What is relative density?
Relative Density is defined as the ratio of mass density of a substance to some standard mass density.
19. What is Ductility?
It is the ability of a material to be permanently deformed without breaking when a force is applied.
20. What is the primary mineral in glass products?
Silica or silicon dioxide (SiO2)
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