Q1: What do you know about elasticity?
Ans:The property of a material by which it returns back to its original position after the removal of external force is called elasticity.
Q2: Define plasticity.
Ans:The property of a material by which it does not return to its original position after the removal of external force is called plasticity.
Q3: Define elastic materials.
Ans:The property of a material by which it returns back to its original position after the removal of external force is called elasticity while such materials are elastic materials.
Q4: Define plastic materials.
Ans:The property of a material by which it does not return to its original position after the removal of external force is called plasticity while such materials are plastic materials.
Q5: Differentiate between perfectly elastic and partially elastic materials.
Ans:The materials that completely return back to their original state after the removal of external force are perfectly elastic materials. The materials that partially (not fully) return back to their original state after the removal of external force are partially elastic materials.
Q6: What is ductility?
Ans:The property of material by which it can be easily stretched into wires and show some warning before failure is ductility.
Q7: Define brittleness.
Ans:The property of material by which it cannot be easily stretched into wires and does not show any warning before failure is brittleness.
Q8: Define ductile material.
Ans:The property of material by which it can be easily stretched into wires and show some warning before failure is ductility and such materials are ductile materials. Example: Concrete.
Q9: Define brittle material.
Ans:The property of material by which it cannot be easily stretched into wires and does not show any warning before failure is brittleness and such materials are brittle materials. Example: Glass.
Q10: Define hardness of material.
Ans:The hardness of material tells about how hard or soft something is. It is resistance against indentation.
Q11: What is the stress-strain curve?
Ans:The curve in which stress is plotted on y-axis and strain on x-axis and point joined as curve is stress-strain curve.
Q12: Enlist different stages that a material passes during tensile tests.
Ans:
- ➔ Limit of proportionality
- ➔ Elastic limit
- ➔ Yield point
- ➔ Ultimate point
- ➔ Breaking point
Q13: Define Yield Point.
Ans:The stress at which a material expands more quickly with no increase in load is Yield Point.
Q14: Differentiate between elastic and plastic ranges.
Ans:The region of stress-strain curve from origin to elastic limit is elastic range. The region of stress-strain curve from elastic limit to rupture is plastic range.
Q15: What is meant by elastic limits?
Ans:It is the limit value at which the material is perfectly elastic. After this limit the material is not perfectly elastic.
Q16: Define ultimate stress.
Ans:The maximum stress that a material can carry without failure is Ultimate or Maximum Stress.
Q17: Define breaking stress.
Ans:The stress at which the material fails and breaks apart is Breaking Stress.
Q18: What do you know about the factor of safety?
Ans:
The ratio of Ultimate Stress to Working Stress is called the Factor of Safety. It is normally 3-5.
Q19: Define Working stress.
Ans:The maximum stress that a material can take without failure is called Working Stress.
Q20: What is meant by the limit of proportionality?
Ans:The value of stress up to which stress and strain remain proportional is the limit of proportionality.
Q21: If the ultimate crushing stress of the cast iron column is 540 MN/m2, then calculate working stress of material. Use Factor of Safety 6.
Ans:
Q22: If the yield load of a 1.4cm diameter mild steel rod is 65000N then calculate the yield stress of the rod.
Ans:
Q23: Differentiate between ultimate point and breaking point.
Ans:The point of maximum stress is Ultimate Point while the stress at which material breaks/fails is Breaking Point.
Q24: Write the formula to calculate Factor of Safety.
Ans:
