Skip to main content

Part -4 Most commonly asked Mechanical Interview Questions

Most commonly asked Mechanical Interview Questions with answer

 1.          What is Difference between stamina and strength?

 Ans.    Strength is capability over a short length of time and Stamina is the ability to keep going continuously.

2.          What is Hydro-static System?

 Ans.    Hydrostatics is the study of fluid bodies that are
  • At rest
  • Moving sufficient slowly so there is no relative motion between adjacent parts of the body
For hydrostatic situations
  • There are no shear stresses
  • There are only pressure forces that act perpendicular to any surface.
It’s a closed loop hydraulic systems. It comprises of motor and pump. Here pump supplies energy to motor and motor gives return energy to pump supply.

3.          What is Cotter joint?

 Ans.     A cotter joint is used to connect rigidly two co-axial rods or bars which are subjected to axial tensile or compressive forces. Here shaft is locked in place by a smaller pin that passes through the side of the lug and partly or completely through the shaft itself. This locking pin is named as cotter.

4.          How is the excess discharge pressure prevented?

 Ans.     Discharge pressure prevented by a pressurized spike cushion. Here the system employs a pressurized cushion of air and a two o-ring piston, which permanently separates this air cushion from the water system. When the valve closes and the water flow is suddenly stopped, the pressure spike pushes the piston up the arrester chamber against the pressurized cushion of air. The air cushion in the arrester reacts instantly, absorbing the pressure spike that causes water hammer.

5.          What is the difference between Strainer and Filter?

 Ans.     Strainer for coarse size, Filter is more accurate than Strainer.

6.          What is the position of Piston Ring?

 Ans.     In 180 degree angle the Top ring, Second ring and Oil ring are fixed. Position the ring approximately 1 inch gap below the neck.

7.          Why Deaerator are placed at Height, In Thermal Power Plant?

 Ans.    To build a Very high pressure and the temperature for a boiler feed water pump and it discharge high pressure water to the boiler.
And to provide the required Net Positive Suction Head (NPSH) for the BFW pump and to serve as a storage tank to ensure a continuous supply of feed water during rapid changes in BFP.

8.          What is meant by One Tonn Air-Conditioner?

 Ans.     1 ton refrigeration means 210 kJ/min extracts heat from the system.

9.          State 1st Law of Thermodynamics?

 Ans.    Heat and mechanical work are mutually convertible. Energy can neither be created nor be destroyed but it can be transferred from one form to another.

 10.          If you heat a steel pipe with the hole at centre, does heat affects the hole diameter?
Ans.     It gets bigger.

 See related more FAQs  <<<< Click Here >>>>



Labels:

Popular posts from this blog

Part -2 Most commonly asked Mechanical Interview Questions

Most commonly asked Mechanical Interview Questions 1. What is the difference between Critical Speed and Whirling Speed? Ans. In Solid mechanics, in the field of rotor dynamics, the critical speed is the theoretical angular velocity which excites the natural frequency of a rotating object, such as a shaft, propeller or gear. As the speed of rotation approaches the objects natural frequency, the object begins to resonate which dramatically increases system vibration. The resulting resonance occurs regardless of orientation.Whirling Speed is due to the unbalanced forces acting on a rotating shaft. 2. How a Diesel Engine Works as Generator? Ans. Diesel engine is a prime mover, for a generator, pump,and for vehicles etc. generator is connected to engine by shaft. mostly in thermal power plat ,there is an engine is used to drive generator to generate power. 3. Explain Second Law of Thermodynamics? Ans. The entropy of the universe increases over tim...
Read more

Part -7 Most commonly asked Mechanical Interview Questions

Most commonly asked Mechanical Interview Questions What are the different types of fits? Explain? On the basis of Indian standards fits can mainly be categorised into three groups: > Clearance Fit : These types of fits are characterised by the occurrence of a clearance between the two mating parts. The difference between the minimum size of the hole and the maximum size of the shaft is called the minimum clearance, the difference between the maximum size of the hole and the minimum size of the shaft is known as maximum clearance. > Interference Fit : In these types of fits the size of the mating parts are predefined so that interference between them always occurs. The tolerance zone of the hole is completely below the tolerance zone of the shaft. > Transition Fit : As the name suggests these type of fit has its mating parts sized limited to allow either clearance or interference. The tolerance zone of the hole and the shaft overlaps in case of such fits. For a shaf...
Read more

ULTRASONIC TEST

ULTRASONIC TEST INTRODUCTION This method is used to test a variety of both metallic & non metallic products such as welds, forgings, castings, sheets, etc. It has an advantage of detecting sub-surface discontinues with accesses to only one side of the specimen. In this method beams of high frequency sound waves are introduced into the material being tested. The sound waves travel through the material with some loss of energy & are reflected back . This is detected & analysed to detect the presence of flaws. This test employs ultrasonic waves. These waves are mechanical waves that consist of oscillations or vibrations. METHOD TRANSMISSION SYSTEM This method employs two Transducers, one for sending & other for receiving the pulses. These may be short or continuous & are transmitted through the material. The result gets displayed on the CRO connected. The settings of the CRO can be adjusted with respect to time & distance. Prior to testing couplant is used to prov...
Read more