Interview Questions Answers in Mechanical Engineering

Question { RRB, 3778 }

The advantage of a controllable pitch propeller?

Answer

Controllable pitch propeller: In Vertical Centrifugal pumps, we can get variable flow at constant speed.

Is This Answer Correct ?

1 Yes

0 No

Question { RRB, 9027 }

What do you call a piston travel from TDC to BDC?

Answer

piston travel from TDC to BDC is called Downward stroke.

Is This Answer Correct ?

0 Yes

0 No

Question { RRB, 5625 }

What is the boiling point of water?

Answer

Boiling point of water is 100 degree Centigrade at Atmospheric pressure at Sea level.

Is This Answer Correct ?

0 Yes

0 No

Question { RRB, 2779 }

What are the causes of high alkalinity in boiler water?

Answer

1. Scale formation
2. Reduction in Cross-sectional area.
3. Flow Reduction.
4. Pressure drop.
5. Turbulence.
6. Pitting Corrosion.

Is This Answer Correct ?

0 Yes

0 No

Question { RRB, 5377 }

What causes damage to impellers?

Answer

1.Abrassives in pumping liquid.
2.Cavitation.

Is This Answer Correct ?

2 Yes

0 No

Question { RRB, 7514 }

What is the function of space heaters for motors?

Answer

I agree with Mr.Javed with small correction. ie To drive out moisture and keep winding Warm.

Is This Answer Correct ?

2 Yes

0 No

Question { RRB, 24761 }

"What are specific heat, latent heat and sensible heat?"

Answer

Specific Heat:It is an amount of heat required to raise the temperature of a unit mass of a substance through 1°C.

Latent Heat:It is an amount of heat required to Change a unit mass of a substance from on phase to another phase at same temperature.

Sensible Heat:It is an amount of heat required to change the temperature of a substance.

Is This Answer Correct ?

23 Yes

0 No

Question { MAHINDRA, 56860 }

1hp=how much rpm

Answer

HP has a direct relation to N(speed) & T(torque). Within limited T, N remains. Current A varies. Hence HP gives constant N (Refer to Nameplate details of Motor),

Is This Answer Correct ?

0 Yes

0 No

Question { 5157 }

How to calculate CFM of fan?

Answer

Duct Cross section Area (in Sq.Feet) X Velocity (Feet/min).

Is This Answer Correct ?

0 Yes

0 No

Question { 6454 }

what is differential expansion?

Answer

Fully agree with Mr. Ch Javed

Is This Answer Correct ?

3 Yes

2 No

Question { 3225 }

how vaccum create in watering vaccum oump?

Answer

When the shaft rotates, Water moves outward and forms a water ring thereby creating a Vacuum inside the ring.
Note: The water ring acts as a seal.

Is This Answer Correct ?

0 Yes

0 No

Question { IGCAR, 14613 }

what different between centrifugal pump and positive
displacement pump

Answer

In general:
Centrifugal pumps are Flow oriented.
Positive displacement pumps are Pressure oriented.

Is This Answer Correct ?

25 Yes

2 No

Question { 7163 }

what is latent heat?

Answer

Latent heat - It is the amount of heat required to change a
unit mass of a substance, from one phase(state) to another
phase(state).

Is This Answer Correct ?

4 Yes

0 No

Question { 5082 }

where multistage pump used

Answer

For high Pressure or Head. But Q remains.

Is This Answer Correct ?

0 Yes

0 No

Question { 5478 }

what is specific heat

Answer

Specific Heat: It is an amount of heat required, to change
the temperature of unit mass of a substance, through 1
degree centigrade.

Is This Answer Correct ?

13 Yes

1 No

abdul hameed