Interview Questions Answers in Mechanical Engineering

Question { Wartsila, 14761 }

what is purpose of governor in desiel engine...

Answer

To maintain the constant speed, irrespective of any load.

Is This Answer Correct ?

3 Yes

1 No

Question { 8532 }

what is the purpose of reheating the fuel in gas turbine

Answer

Purpose of reheating the fuel in gas turbine: When reheating the Fuel, it looses the viscosity so that it can be fully atomized, to get complete Combustion.
The Cold fuel will lead to Incomplete combustion and leave the un-burned fuel accumulation. This will be highly dangerous as it can get self Ignited and will lead to sudden Explosion.

Is This Answer Correct ?

0 Yes

0 No

Question { 9349 }

NPSH for centrifugal pump

Answer

NPSH: Net Positive Suction Head.
By definition:NPSH is an algebric sum of all the heads
(atmospheric head,vapour head, friction head, static head)
available at the suction eye of an impeller.

Is This Answer Correct ?

6 Yes

2 No

Question { IGCAR, 7727 }

Explain QH curve of a Centrifugal Pump?. Will it ever touch
X axis?. If it ever touch when?
When will you go for Reciprocating pump?. why can't you use
centrifugal pumps for pumping viscous fluids?. Why head of
a centrifugal pump is independent of density of fluid?.

Answer

QH curve of a Centrifugal Pump: As Head increases, Quantity decreases. It will never touch X axis, because, X axis is the center line of the pump.

Is This Answer Correct ?

2 Yes

0 No

Question { IGCAR, 2499 }

Two pumps connected in series , what will be the shape of
QH curve ?. What will be the shape if they are in parallel.

Answer

Two pumps connected in series: H will be more & Q will be same.
Two pumps connected in parallel: H will be same & Q will be more.

Is This Answer Correct ?

0 Yes

0 No

Question { 9007 }

What are the protections required to protect turbine?

Answer

Turbine Supervisory control system contains all protection as written by Mr. devanesan & Mr.g.janardhan.

Is This Answer Correct ?

0 Yes

2 No

Question { 6311 }

What is the difference between speed and velocity?

Answer

In General:
Speed: It can either be a Angular or Linear movement per unit time.

Velocity: It is a Linear movement per unit time.

Is This Answer Correct ?

0 Yes

0 No

Question { 2332 }

if there is 30% loss in cooling of an ic engine then to
reduce that it is ok to supply 30% less fuel? why?

Answer

Loss of cooling is a deficiency to be rectified. Instead Reducing fuel is illogical.

Is This Answer Correct ?

0 Yes

0 No

Question { 4604 }

What type of pump is commonly used is feed water system in
boiler?

Answer

Multi Stage Centrifugal pump.

Is This Answer Correct ?

1 Yes

0 No

Question { 4200 }

Which pump is better : a) with Less NPSHr or b) with more
NPSHr

Answer

a) with Less NPSHr

Is This Answer Correct ?

7 Yes

2 No

Question { ME, 3735 }

what is the hrc

Answer

hrc - It is an abrivation for "Rockwell Hardness" - used to
measure the meterial hardness. There is also another
unit"Brinnel Hardness"

Is This Answer Correct ?

7 Yes

0 No

Question { 2942 }

In a 4 cycle engine the intake valve begins to open at?

Answer

In a 4 cycle engine the intake valve begins to open just before the piston reaches to Top Dead Center (During Exhaust Stroke).

Is This Answer Correct ?

2 Yes

0 No

Question { 2502 }

The advantage of a controllable pitch propeller?

Answer

We can get Variable Flow at Constant Speed.

Is This Answer Correct ?

0 Yes

0 No

Question { TATA, 4220 }

What is a brake horse power?

Answer

It is the actual Output of an engine (neglecting all
losses) @ BHP=IHP-FHP.
It is used for engineering calculations.

Is This Answer Correct ?

5 Yes

0 No

Question { 3882 }

What should you do before you start the engine?

Answer

Before starting the engine, Lub oil system and cooling water system must be put in service.

Is This Answer Correct ?

0 Yes

0 No

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