How to check isro application status?
No of independent elastic constant for homogeneous or isotropic? It's 2 or 3 ?
addition of copper to aluminum results in
- precipitation hardening
- high machinability
- grain refinement
- corrosion resistance
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what is precipitation hardening and anodizing
corrosion resistance of steel increases by addition of
- chromium,nickel
- vanadium,aluminium
- sulphur,phosphorous,lead
- tungsten,molebdenum,vanadium,chromium
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For one dimensional isentropic flow in a diverging passage,if initial static pressure is p1 and initial mach number is m1 then for downstream flow
- m2<m1,p2>p1
- m2>m1,p2>p1
- m2p1
- m2>m1,p2<p1
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necessary precaution in selection of pumps for parallel operation is
- both pumps r same
- H-Q of both are same
- both pumps r centrifugal
- no change from positive to negative slope in H-Q curve
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1) At a point of maximum bending moment, shear force must be 0 (True/False)
2)At a point of maximum shear force, bending moment = 0 (True/False)
Rate of change of bending moment is shear force
Rate of change of shear force is intensity of loading
At point of maximum bending moment shear force = 0
At point of maximum shear force BM need not be zero
There is no need that BM is maximum at all 'zero' shear force points; however at max BM, SF = 0
Point of inflection is the point, where BM = 0
Point of contra flexure is the point, where BM is changing it's sign
As 'Axial Rigidity' (AE) increases ---> 'Stiffness' increases ----> 'Deflection' decreases in a prisamatic bar.
As 'Flexural Rigidity'(EI) increases ---> 'Rigidity' increases ---> 'Deflection' decreases in a beam
As 'Section Modulus' (Z) increases ----> 'Strength' of the beam increases
Z is a strength parameter; strength of beam = Z = ( I / Ymax ).
The ratio of section modulus 'Z' for a square and diamond cross section is 'root2'
When a solid beam is sliced horizontally into 'n' slices the strength of the beam reduces by 'n' times i.e., Zsolid / Zsliced = n.
When a solid beam is sliced vertically into 'n' slices the strength of the beam remains same i.e., Zsolid /Zsliced = 1;
Every one is talking about rk jain book ...is that very useful
In arc welding, penetration is minimum for Dcsp Dcrp Ac Dcen
In resistance welding, heat is generated due to resistance bw
- Electrode and workpiece
- Asperities bw touching plates
- Two dissimilar metals in contact
- Interatomics forces
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Incorrect statement about fn of flux in brazing
- To prevent oxides from forming during brazing on both base metal and the brazing material
- To dissolve surface oxide coatings formed prior to brazing
- To avoid thermal distortion and cracking
- To facilitate the wetting process by reducing the viscosity of the melt
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1. In case of low carbon steels (e.g.: mild steel)
Stress corresponding to UpperYieldPoint depends on a) area of cross section b) shape of cross section
Stress corresponding to LowerYieldPoint does not depends on area and shape of cross section. Hence LowerYieldPoint is more reliable and is considered for design.
The LowerYieldPoint for all shapes and sizes of mild steel is 250Mpa
2. FOS: factor of safety
FOS = (YieldStress / WorkingStress) for ductile materials
FOS = (UltimateStress / WorkingStress) for brittle materials
MOS = Margin of safety
MOS = FOS -1
3. The common failure in ductile materials is 'cup-cone' failure and this failure is due to shear.
4. In case of high carbon steel, as it does not have a well defined yield point; oxide method (usually 0.2%strain) is used to determine the proof stress. This proof stress is considered for the design.
5. In brittle materials, ultimate stress is considered for design.
To get a good surface finish on a turned job, one should use a sharp tool with a ... feed and ... speed of rotation of the job
- Min, min
- Min, max
- Max, min
- Max, max
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Do you guys think there might be question(s) from slopes and deflections of beams (Double integration method, conjugate beam method) ?
Internal and external threads are produced on tapered surfaces conveniently by
- Lathe
- Universal milling mc
- Plano miller
- Planetary milling mc
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Do any 1having answers of ISRO mechanical papers from 2007-2011..? Can you please mail me at [email protected]...? Thanq in advance..:-)