some mechanical Inerview questions : * Which Mechanism is used in Automobile gearing system ? --> Differential mechanism * Why different types of sound are produced in different bikes though they say run on SI engine ? --> Engine specifications are different in different manufactures like as Bore Diameter(CC), Ignition timing. Also the exhaust * Why entropy decreases with the increase in temperature? --> ds=dQ/TEntropy is inversely proportional to the temperature so.as temp. increases,entropy decreases. * 1 hp how much watt? --> 746.2Watt * Poisons ratio is higher in (rubber/ steel/wood) ?? --> When a material is compressed in one direction, it usually tends to expand in the other two directions perpendicular tothe direction of compression. This phenomenon is called the Poisson effect. Poisson’s ratio is a measure of the Poisson effect. For rubber = 0.5 For steel = 0.288 For wood < 0.2 Thus Poisson’s ratio is higher in RUBBER. * The Fatigue life of a part can be improved by ? --> Improving the surface finish by Polishing & providing residual stress by Shot peening. * How to know whether the valve is inlet or exhaust by seeing the engine? --> Inlet valve has more diameter than exhaust valve. * what is the rpm of steam engine? --> 200rpm * What are the different classes of metal alloys? --> Ferrous ( cast iron---carbon steels--- high alloy steel (tool steel & stainless steel) and Non Ferrous like Aluminium, Copper, Magnesium, Titanium, Zinc. * What is the difference between BSP thread and BSW thread? The British Standard Pipe thread (BSP thread) is a family of standard screw thread types that has been adopted internationally for interconnecting and sealing pipe ends by mating an external (male) with an internal (female) thread. British Standard Whitworth (BSW) is one of a number of imperial unit based screw thread standards which use the same bolt heads and nut hexagonal sizes. * How Cavitation can be eliminated in a Pump? --> Cavitation means bubbles are forming in the liquid. · To avoid Cavitation, we have to increase the Pump size to One or Two Inch; · To increase the pressure of the Suction Head, or · Decrease the Pump Speed. * Which pump is more efficient Centrifugal pump or Reciprocating pump? --> Centrifugal pump. Because flow rate is higher compared to reciprocating pump. Flow is smooth and it requires less space to install. Lower initial cost and lower maintenance cost.
Posted on: Wed, 21 Aug 2013 05:00:07 +0000
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