Latest Updates in Mechanical Engineering

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  • 1hp=how much rpm

We need Torque to find out.

Apply this formula:

T = HP x 5252
           rpm

T = torque (in lb-ft)
HP = horsepower
5252 = constant
rpm = revolutions per minute

  • which mechanism is used in automobile gearing system

Differential mechanism

  • why different types of sound are produced in different bikes though they say run on SI engine

Engine specifications are different in different manufactures like as bore diameter(cc),ignition timing.Also the exhaust passage take more responsible for sound.

  • why entropy decreases with the increase in temperature?

ds=dQ/T

Entropy is inversely proportional to the temperature so.as temp. increases,entropy decreases

  • What type of metal is used in a propeller

Aluminium,stainless steel,magnesium bronze,NIBRAL(nickel,brass,aluminium)

  • why involute curve used in gear

1) it’s smooth to drive the gear.
2) in gears contact is only point, this type is curve take the more load than normal one

  • How Trains take turns, though there is no any differential

Purpose of the differential is to enable vehicles to take turn, by allowing both the wheel to rotate with different speed. This is required when wheels, like in car, are connected with same axle. Interestingly, wheel in trains are not connected with the axle, they are independent and hence can take turns without ant differential. This is same as how the bullock cart takes turns, without any differential.

  • In condensation of steam power plant, steam sent in shell side and cooling water on the tube side because
    1. To increase overall heat transfer coefficient of water side velocity can be increases if water is on the tube side
    2. Condenser can act as a storage unit for condensed steam
    3. Rate of condensation of steam is invariably smaller than the mass flow rate of cooling water
    4. It is easier to maintain vacuum on the shell side than on the tube side

Answer:

1. To increase overall heat transfer coefficient of water side velocity can be increases if water is on the tube side

Reason:

Specific volume of steam is larger so more volume is required in condenser

  • Why freezer in the fridge is placed in top level?

Because density of cold air is higher than warm air,hence itis placed at top.Cold air comes downward & cool the bottom part.

  • what is more dangerous longitudinal stress or Hoop stress and why?

Hoop stress is more dangerous thanlongitudinal stress, because the dangerous area coming underthe hoop stress is circumferential,while in longitudinal,theaxial area will come under dangerous area will will be lessthan circumferential area.So the hoop stress is more dangerous than longitudinal stress

  • In a spray washing system, if the water temperature is higher than the dry bulb temperature of entering air then the air is
    1. Heated and dehumidified
    2. Heated and humidified
    3. Cooled and humidified
    4. Cooled and dehumidified

Answer:

Heated and humidified

Interview Questions On Strength of Materials | Questions Asked in Mechanical Engineering Interview

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Interview Questions On Strength of Materials and Questions Asked in Mechanical Engineering Interview

Here in this article, check the interview questions on Strength of Materials and questions asked in Mechanical Engineering interview panels.

1. Can anybody please provide any link to calculate force required to bend a metal sheet into pipe? or describe how is it calculated?

It depends upon the thickness of sheet and required diameter to be formed from the sheet.

2. A bearing designated as 6205 , what is it’s bore diameter:

Generally for bearing bore diameter is 5 times the last number in its designation i.e. for designation 6205, Bore diameter should be 25

3. Where half nut is use

the half hut is use in lathe .in this half nut mechanism is engaged during the thread cutting operation.and it connect carriage and lead screw.it having 2 portion one half is fixed and one movable.

4. Why the rail in form of I-beam?

It’s flexural rigidity is high and it’s cross section consume low metal.

5. Aluminium foil used for cooking food and storage has one shiny surface and one dull surface. Which surface side be on the outside when the food wrapped for baking and freezing respectively.

  1. Shiny side, shiny side
  2. Dull side, dull side
  3. Shiny side, dull side
  4. Dull side, shiny side

Answer:

Dull side, Shiny side

Reason:

  • The shiny surface of foil loses heat through radiation much faster than the dull surface.
  • When the food baked shiny surface kept inside, so the heat kept inside and not to leave.
  • When the food freeze shiny surface kept outside, so the loss of heat radiated faster which keeps the food in cool.

6. What is difference between pressure and stress?

When the force or load acting on the fluid (pneumatic or hydraulic) per unit area is known as PRESSURE.. its purely subjected to fluids……..

when the force or load acting on the object (solid) within the elastic limit of an object create internal resistance to resist the apply load. that internal resistance is known as STRAIN for per unit area of that object.. Its mainly subjected to solids…

7. Is there any rake angle in blade? which used to shave the beard ?

it consists of negative rake angle.

8. Stress strain diagram for fluid

Parallel line horizontal to stress axis

9. What’s the range of poisons ratio of a stable material?

Theoretical values are — -1 to 0.5

Practical values are — 0 to 0.5

10. Why 220 V A.C. is more dangerous than 220 V D.C

  1. The D.C. attracts
  2. Peak voltage for A.C. is much larger
  3. The body offers less resistance to A.C.
  4. Due to some other reasons

Answer:

Peak voltage for A.C. is much larger

Reason:

D.C. = 220 volt

A.C. = 1.414 x 220 volt

11. What is the difference between limit of proportionality and elastic limit

Up to the limit of proportionality stress is directly proportional to strain,follows hooks law,elastic limit is limit for elasticity of material.