INTERVIEW QUESTIONS OF STRENGTH OF MATERIAL

INTERVIEW QUESTIONS OF STRENGTH OF MATERIAL 

1.)What are the units for Poisson’s ratio?

It is a unit less quantity. Because it is one quantity divided by another quantity of the same units.In fact, even the parent quantities that define Poisson’s ratio are unit less. Strain has no units.

2.)What is the difference between Stress and Pressure?
Stress=Resistive force/Area.
Pressure=Force/Area.
Stress is pull force and Pressure is push force.

3.)Difference between Performance and Efficiency?

Performance is the measure of quality of the work done by any machine. better  the quality better will be the performance of that machine. while efficiency is the ratio of desired output to the required input for any machine.

Performance is about the quality that a machine or plant is producing suppose there are two machines, first produces the job of accuracy .002mm and the second one produce product of the accuracy .001mm. then the second one will have higher performance.  while efficiency is the ratio of the o/p to the i/p. if same machines are producing 200 and 100 product per day respectively for the same i/p,then the eff. of the first machine will be high.

4.)What are the causes of main engine black smoke?

There is many cause of black smoke.

a. It’s improper mixture of fuel supply by carburetor like very rich mixture so the fuel improper burn.

b. It’s when piston or piston ring is fail so back side cooling oil release in combustion chamber it cause black smoke.

c. Improper ignition system like not sufficient time of pressure rise delay period.

5.)What is structurally stronger, solid steel or hollow steel?

If a solid and hollow shape have the same outside dimensions, the solid one is clearly stronger.The reason you see so many hollow sections is that they have an incredibly higher strength/weight ratio and can resist the same load with much less material used..