Latest Mechanical Interview Questions & Answers | Thermal Interview Q & A | Automobile Interview Q & A

01-Technical Interview questions-how to prepare for technical interview-job interview-getting a job

  • What happens if gasoline is used in a Diesel engine?Diesel engine will work ?

No, It will not work,as the Compression ratio of Petrol engine is 6 to 10 & that of Diesel engine is 15 to 22. Thus on such high compression, gasoline gets highly compressed & it may blast.

  • 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/TEntropy is inversely proportional to the temperature so.as temp. increases,entropy decreases.

  • 1 hp how much watt?

746.2Watt

  • How to calculate bearing number to diameter of the inner and outer

Divide the shaft diameter size by 5, it will give last two digitof the bearing no. and according to type of load we have tochose the type of bearing and that will give prior no. ofthe bearing.

  • Explain Bicycle rear wheel Sprocket working?

Rear wheel sprocket works under the principle of ratchet and pawl.

  • In a domestic refrigerator, a capillary tube controls the flow of refrigerant from the
    1. Expansion valve to the evaporator
    2. Evaporator to the thermostat
    3. Condenser to the expansion valve
    4. Condenser to the evoparator
Read More Info Regarding This Post :   What is WEP

Answer:

Exapansion valve to the evaporator

Reason:

A capillary tube is the replacement of thermostatic valve and connects expansion valve to the evaporator

  • Definition of Octane number & Cetane number

Octane No.- Octane number is defined as the percentage, by volume, of iso octane in the mixture of iso octane and h-heptane. It is the measure of rating of SI engine.

Cetane No.- Cetane number is defined as the percentage, by volume, of n-cetane in the mixture of n-cetane and alpha methyl naphthalene. It is the measure of rating of CI engine.

  • Poisons ratio is higher in (rubber/steel/wood)

When a material is compressed in one direction, it usuallytends to expand in the other two directions perpendicular tothe direction of compression. This phenomenon is called thePoisson effect. Poisson’s ratio is a measure of the Poisson effect.

Read More Info Regarding This Post :   Latest Placement Papers in Mechanical

For rubber = 0.5

For steel = 0.288

For wood < 0.2

Thus Poisson’s ratio is higher in RUBBER.

  • The Fatigue life of a part can be improved by ?

Improving the surface finish by Polishing & providing residual stress by Shot peening.

  • The commonly used material for insulator of spark plug is
    1. Bekelite
    2. Asbestos
    3. Alumina
    4. Copper

Answer:

  1. Alumina
  • When crude oil heated Which Hydro carbon comes first?

Natural gas(Gasoline)… at 20 Celsius

Sending
User Review
( votes)

3 comments

  • i’m try to 1st really, this is the best site for all information who is related to mechanical student.thanks lot of.

  • fakorede gabriel

    this is a wonderfully packed blog for mechanical engineering student. so beauty enough to revisit often and often

  • the 1st answer is half correct and half wrong.. the engine wont get blasted when we use petrol in diesel engine.. rather the power stroke starts earlier, before attaining the full compression so the engine stop to work.

Leave a Reply

Your email address will not be published. Required fields are marked *