MECHANICAL ENGINEERING JOB INTERVIEW QUESTIONS

1.)What is the difference between alpha iron, delta iron and gamma iron ?

Ans: The bcc form of iron exists between room temperature and 910°C, and between 1400°C and the melting point at 1539°C. The lower temperature form is known as "alpha"-iron and the higher temperature form as "delta"-iron. The face-centered cubic form existing between 910°C and 1400°C is referred to as "gamma-iron".

2.)Explain the difference between the points of inflexion and contraflexure.

Ans: At points of inflexion in a loaded beam the bending moment is zero and at points of contraflexure in loaded beam the bending moment changes sign from increasing to decreasing.

3.)What do you understand by eutectic ?

Ans: It is mechanical mixture of two or more phases which solidify simultaneously from the liquid alloy.

4.)Under what condition a convergent divergent nozzle required ?

Ans: When pressure ratio is greater than critical pressure ratio