Most commonly asked Mechanical Interview Questions 1. Why Entropy decreases with increase in temperature? Ans. ds=dQ/T Entropy is inversely proportional to the temperature so, as temp. Increases, entropy decreases. 2. Why different types of sound are produced in different bikes, though they run on SI Engines? Ans. Engine specifications are different in different manufactures like as Bore Diameter (CC), Ignition timing. Also the exhaust passage takes more responsible for sound. 3. How much Watt means 1Hp? Ans. 746.2 Watt 4. Explain Bicycle Rear Wheel Sprocket working? Ans. Rear wheel sprocket works under the principle of ratchet and pawl. 5. Definition of Octane Number and Cetane Number? Ans. Octane No.- Octane number is defined as the percentage, by volume, of iso octane in the mixture of iso octane and h-heptane. It is the measure of rating of SI engine. Cetane No.- Cetane number i