-----------Interview Question for Freshers---------------------
1. Tell me about your self
Ans: Brief only the achievements and how you did things to grow in technical & other aspects.
2. What are achievement you made so far.
Ans: Explain about the Paper presentation and explain about improvements parts of the paper presentation related suitable example.
3. Where you will be see you after 5 years.
Ans : Explain very minor context and explanation shall be connected to the your goals or aspiration with respective to the Resume.
4. What is your motive towards the professional career or what makes you to select this job .
Ans : Explain the goal towards the job profile how you will be achieving with your technical skill.
Technical Questions-Mechanical
1.The Difference Between True Stress and Engineering Stress?
Ans :
Think about pulling a bar in tension. Load divided by cross-sectional area is
force, or stress. But what cross section
are you considering? Before starting
pull, the bar had a known cross-section of (let’s say) 0.5" wide x metal
thickness. It's easy to measure these,
since it is your starting material. At
any load, the engineering stress is the load divided by this initial cross-
area. While you are pulling, the length
increases, but the width and thickness shrink.
At any load, the true stress is the load divided by the cross-area at
that instant. Unless thickness and width
are being monitored continuously during the test, you cannot calculate true
stress. It is, however, a much better
representation of how the material behaves as it is being deformed, which
explains its use in forming simulations.
In circle grid analysis, engineering strain is the % expansion of the
circle compared to the initial diameter of the circle. The relationships between engineering values
and true values are:
σ = s (1+e) ε = ln
(1+e)
Where "s" and "e" are the engineering
stress and strain, respectively, and "" and "" are the true
stress and strain, respectively.
2. Difference between engineering stress-strain and true stress-strain curve?
Engineering stress and strain (also
sometimes called nominal stress and strain) are calculated based on the
original dimensions of the material.
True stress and strain are calculated
based on the actual dimensions of the material.
So when you do a tension test, the bar
will begin to get thinner as it stretches. Engineering stress would be the
force divided by the original area for the duration of the test. True stress
would be the force divided by the actual area, at every time that a measurement
is taken.
3.What are the different types of fits? Explain?.
Engineering stress and strain (also
sometimes called nominal stress and strain) are calculated based on the
original dimensions of the material.
True stress and strain are calculated
based on the actual dimensions of the material.
So when you do a tension test, the bar
will begin to get thinner as it stretches. Engineering stress would be the
force divided by the original area for the duration of the test. True stress
would be the force divided by the actual area, at every time that a measurement
is taken.
3.What are the different types of fits? Explain?.
Ans:
1.
Clearance fit. In this type of fit, the size limits for
mating parts are so selected that clearance between them always occur. It may
be noted that in a clearance fit, the tolerance zone of the hole is entirely
above the tolerance zone of the shaft. In a clearance fit, the difference
between the minimum size of the hole and the maximum size of the shaft is known
as minimum clearance whereas the difference between the maximum size of the
hole and minimum size of the shaft is called maximum clearance. The clearance
fits may be slide fit, easy sliding fit, running fit, slack running fit and
loose running fit.
2. Interference fit. In this type of fit, the
size limits for the mating parts are so selected that interference between them
always occur. It may be noted that in an interference fit, the tolerance zone
of the hole is entirely below the tolerance zone of the shaft. In an
interference fit, the difference between the maximum size of the hole and the
minimum size of the shaft is known as minimum interference, whereas the
difference between the minimum size of the hole and the maximum size of the
shaft is called maximum interference. The interference fits may be shrink fit,
heavy drive fit and light drive fit
3. Transition fit. In this type of fit, the
size limits for the mating parts are so selected that either a clearance or
interference may occur depending upon the actual size of the mating parts. It
may be noted that in a transition fit, the tolerance zones of hole and shaft
overlap. The transition fits may be force fit, tight fit and push fit.
4. What is the difference between modulus of elasticity and
modulus of rigidity?
Ans:
- Modulus of rigidity is valid for both elastic and non-elastic deformations while modulus of elasticity is only valid for elastic deformations.
- Elastic deformation is defined for forces normal to the surface while modulus of rigidity is defined for forces acting along the surface parallel to it.
- The deformation for the modulus of elasticity is linear while the deformation for the modulus of rigidity is a circular one.