MECHANICAL ENGINEERING JOB INTERVIEW QUESTIONS

1.)What is the name given to process of removing non condensables in steam and other vapor cycles ?

Ans: Deaeration process.

2.). We often come across use of jet pumps in process industry ? What is the reason for this ?

Ans: Jet pumps are easy to maintain and can be used to transport gases, liquids and mixtures of both.

3.)When it can be said that a fluid is Newtonian ?

Ans: When the shear stress is directly proportional to velocity gradient.

4.)Out of 2 stroke SI engine, 4 stroke SI engine, and 4 stroke CI engine, how the brake thermal efficiency behaves if these are to be used for road vehicles ?

Ans: 4 stroke CI engine has highest brake thermal efficiency followed by 4 stroke SI engine and the 2 stroke SI has lowest brake thermal efficiency

MECHANICAL ENGINEERING JOB INTERVIEW QUESTIONS

1.)What is operating pressure?

Ans.-Operating pressure is the standard level of pressure a system operates under, usually within a fairly narrow range of tolerances.

2.)Explain Otto cycle.

Ans.-An Otto cycle is an idealized thermodynamic cycle which describes the functioning of a typical spark ignition reciprocating piston engine,the thermodynamic cycle most commonly found in automobile engines.he Otto cycle consists of adiabatic compression, heat addition at constant volume, adiabatic expansion, and rejection of heat at constant volume.

3.)What is annealing?

Ans.-The steady heating of a metal at a certain temperature above the recrystallization phase followed by a gradual cooling process is called annealing.

4.)What is Carburizing?

Ans.-A surface hardening method that heats metal within a carbon-rich environment to increase carbon levels on the metal surface for added hardness is called Carburizing.

MECHANICAL ENGINEERING JOB INTERVIEW QUESTIONS

1.)Why excess air is required to burn a fuel completely ?

Ans: Excess air is required to ensure adequate mixing of fuel and air, avoid smoke, minimize slagging in coal burning, and to ensure maximum steam output.

2.)At what pressure and temperature the density of water and steam is same ?

Ans: At 225 kg/cm2 and 74.6° C.

3.)What is meant by quality of steam ?

Ans: It refers to amount of unevaporated moisture in steam. If steam is perfectly dry, it's quality is 100%.

4.) Why the efficiency of superheat Rankine cycle is higher than that of simple Rankine cycle?

Ans: Because the mean temperature of heat addition is higher for superheat cycle.

MECHANICAL ENGINEERING JOB INTERVIEW QUESTIONS

1.)What is the difference between Technology and Engineering?

Ans. Engineering is application of science. Technology shows various methods of Engineering. A bridge can be made by using beams to bear the load,by an arc or by hanging in a cable; all shows different technology but comes under civil engineering and science applied is laws of force/load distribution.

2.)What is the difference between Speed and Economic Speed?

Ans. The rated speed tells us about the maximum speed which can be achieved by a vehicle or some other machine but the economical speed means the speed limit at which the machine works efficiently with least consumption of fuel.eg-in normal bikes(not racing),the max.speed limit shown on speedometer is upto 120 kmph but companies always advice their customers to drive such bikes at around 60 kmph to have maximum mileage.

3.)Besides lubrication, what are two functions of lubricating oil in some turbines?

Ans.In larger units, lube oil cools the bearings by carrying off heat to the oil coolers. Lube oil in some turbines also acts as a hydraulic fluid to operate the governor speed-control system.

MECHANICAL ENGINEERING JOB INTERVIEW QUESTIONS

1.). What is factor of evaporation ?

Ans: It is the ratio of heat change from feed water to steam and the heat of vaporization of steam at atmospheric pressure.

2.)Which parameters influence the performance of gas turbines ?

Ans: Ambient conditions, inlet/exhaust pressure losses, fuels, and water/steam injection flow rates'influence the performance of gas turbines.

3.)Why steam is in open space and water inside tube in condensers used in power plants ?

Ans: Overall heat transfer coefficient can be increased by increasing velocity of water in tube. Further steam needs more space due to higher specific volume.

4.)What is radiosity ?

Ans: It is the rate at which radiation leaves a surface.