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Part -1 to 8 Most commonly asked Mechanical Interview Questions with answer

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Part -2 Most commonly asked Mechanical Interview Questions

Most commonly asked Mechanical Interview Questions 1. What is the difference between Critical Speed and Whirling Speed? Ans. In Solid mechanics, in the field of rotor dynamics, the critical speed is the theoretical angular velocity which excites the natural frequency of a rotating object, such as a shaft, propeller or gear. As the speed of rotation approaches the objects natural frequency, the object begins to resonate which dramatically increases system vibration. The resulting resonance occurs regardless of orientation.Whirling Speed is due to the unbalanced forces acting on a rotating shaft. 2. How a Diesel Engine Works as Generator? Ans. Diesel engine is a prime mover, for a generator, pump,and for vehicles etc. generator is connected to engine by shaft. mostly in thermal power plat ,there is an engine is used to drive generator to generate power. 3. Explain Second Law of Thermodynamics? Ans. The entropy of the universe increases over tim...
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LIQUID (DYE) PENETRATION TEST (D.P.T.)

LIQUID (DYE) PENETRATION TEST INTRODUCTION A liquid penetrant test is non-destructive type of testing to detect flaws that are open to the surface. e.g. cracks, seams, laps, lack of bond, porosity, cold shuts etc. can be effectively used not only in the inspection of ferrous metals but is especially useful for non-ferrous metal products and on non-porous, non-metallic materials such as ceramics, plastics and glass. PRINCIPLE OF OPERATION The principle of liquid penetrant test is that the liquids used enter small openings such as cracks or porosities by capillary action. They are influenced by factors such as the condition of the surface of material and the interior of the discontinuity. For liquid to penetrate effectively, the surface of the material must be thoroughly cleaned of all material that would obstruct the entrance of the liquid into the defect. After cleaning, the liquid penetrant is applied evenly over the surface and allowed to remain long enough to permit penetration i...
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VISUAL INSPECTION OF WELDING

VISUAL  INSPECTION OF WELDING INTRODUCTION Inspection starts with examination of the material prior to fabrication, scabs, seams, scale or other harmful surface conditions may be detected in visual inspection. The inspector should check the following : Weld preparation, dimensions and finish.  Clearance dimensions of backing strips.  Alignment and fit up to the pieces being welded.  Verification of cleanliness.  Visual Inspection During Welding Visual inspection checks details of the work while welding is in progress. Among the details to be checked are : Welding process.  Cleaning.  Preheat and inter pass temperature.  Joint preparation.  Filler metal.  Flux or shielding gas.  Chipping, grinding, or gouging.  Post heating temperature and time.  Visual Inspection After Welding Visual inspection is useful for finished-product verification of such items as : Profile irregularities of the weldment....
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