Diploma Mechanical Engineering Interview Questions and Answers

Build your knowledge through some of the Diploma Mechanical Engineering Interview questions and answers given here. There are many job opportunities for Diploma in Mechanical Engineering candidates. Diploma of Mechanical Engineering has its uses in all fields of technology. Every manufacturing and production industry needs mechanical engineers to carry out jobs for their companies. Thus, Diploma Mechanical Engineering has always been in demand and will continue to remain in the future. Below are some of the frequently asked Diploma Mechanical Engineering Interview questions and answers.

1 Q: What is Carnot engine?

A: Carnot engine or Carnot cycle describes a heat engine that uses reversible processes that can be handled theoretically. Carnot engine is an imaginary engine which follows the Carnot cycle and provides 100% efficiency.

2 Q: What is Hess law?

A: Hess Law states that the heat evolved or absorbed in a chemical process is the same whether the process takes place in one or in several steps. This is also known as the law of constant heat summation.

3 Q:. What is the importance of the Thermodynamics in the field of Mechanical Engineering?

A: Thermodynamics are involved in many of the areas where a mechanical engineer might be working. That includes engines, turbines, compressors, pumps, boilers, heat exchange and refrigeration. Hence, Thermodynamics are of great importance in the field of mechanical engineering.

4 Q: State laws of conservation of energy.

A: The law of conservation of energy is a law of science that states that energy cannot be created or destroyed, but only changed from one form into another or transferred from one object to another.

5 Q:. What is DTSI technology?

A: DTSI stands for Digital Twin spark Plug Ignition. The vehicles with DTSI technology use two spark plugs which are controlled by digital circuit. The concept behind that is to reduce the unburnt fuel inside the engine cylinder thereby increasing the power.

6 Q:. State the difference between Critical speed and Whirling speed.

A: In Solid mechanics, in the field of rotor dynamics, the critical speed is the theortical 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.

7 Q:. State the second law of thermodynamics

A: The second law of thermodynamics is a general principle which places constraints upon the direction of heat transfer and the attainable efficiencies of heat engines. In doing so, it goes beyond the limitations imposed by the first law of thermodynamics.

8 Q:. What is the purpose of scraper rings?

A: Scraper rings are solely used for the purpose of scraping oil from the liner after the lubrication action is over. These rings do not allow oil to pass from between the face of the ring and the cylinder.

9 Q:. What is the difference between welding and brazing?

A: Welding is a process in which two or more metals will be melted to their melting point and are joined together by hammering. It is mainly used in construction and industrial fields. Whereas brazing is a process in which a filler material will be heated up to its melting point by using flame or electric arc so that the filler material will turn into liquid state and settle into the gas between two metals. Brazing is mainly used in soft applications.

10 Q: What is a cotter joint?

A: Cotter Joint is a flat wedge shaped part of rectangular cross section with its thickness is tapered as of one end to an extra for a simple adjustment. Cotter joint is provisional fastening which is used to attach firmly two co-axial rods and bars which are subjected to axial tensile or compressive forces.

11 Q:. What is the difference between unilateral tolerance and bilateral tolerance?

A: Tolerance is the difference between the upper limit and lower limit of a dimension, that is, it can also be defined as the maximum permissible variation in a dimension. The tolerance can be unilateral or bilateral. When the entire tolerance is allowed on one side of the nominal size it is said to be unilateral system of tolerance which is mostly used in industries. When the tolerance is allowed on both the sides of the nominal size then it is said to be a bilateral system of tolerance.