Monday, October 31, 2016

mechanical-page3

16. What is isometric drawing?

Ans:
It is a 3-D drawing used by draftsmen, architects etc

17. What is a Process Flow Diagram?

Ans:
A Process Flow Diagram (or System Flow Diagram) shows the relationships between the major components in the system. It also has basic information concerning the material balance for the process.

18. Is it the stress that, produces strain or strain produces stress?

Ans:
A Force applied to an object will cause a displacement. Strain is effectively a measure of this displacement (change in length divided by original length).
Stress is the Force applied divided by the area it is applied. (E.g. pounds per square inch)
Therefore, to answer the question, the applied force produces both “Stress and Strain”. “Stress and Strain” are linked together by various material properties such as Poisson's ratio and Young's Modulus.

19. What are the points in the stress strain curve for steel?

Ans:
Proportional limit, elastic limit or yield point, ultimate stress and stress at failure.

20.State Newton's three laws of Motion.

Ans:

  • The law of inertia: Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.
  • Acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object). Force=Mass times acceleration.
  • For every action there is an equal and opposite reaction.



21.State the laws of thermodynamics?

Ans:
Thermodynamics is a physical science which studies the interrelation between heat, work and the internal energy of any system. Thermodynamics helps study all the systems of mechanical engineering. There are three laws of thermodynamics.

First Law: Energy can be neither created nor destroyed. It can only change forms. In any process in an isolated system, the total energy remains the same.

Second Law: The second law of thermodynamics states that the entropy of any isolated system not in thermal equilibrium almost always increases.

Third Law: As temperature approaches absolute zero, the entropy of a system approaches a minimum.

22.What is Hess law?

Ans:
According to the Hess law the energy transfer is simply independent of the way being followed. If the reactant and the product of the whole process are the same then same amount of energy will be dissipated or absorbed.

23.Explain what is torque?

Ans:
Torque is the force that causes rotation. It is a measure of how much force is acting on an object making it rotate.

24.What is the difference between torque and power?

Ans:
While power determines the speed of a vehicle, torque determines the time in which that speed can be reached. The greater the torque figure, the faster the acceleration. The more torque in the engine, the faster you accelerate. Power is the rate at which work is done, so it is basically the potential of the engine.

25. What is fuel ratio ?

Ans:
Fuel ratio is the ratio of its % age of fixed carbon to volatile matter.





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