Latest Mechanical Interview Questions

1.          What is the difference between Fan and Blower?
Ans.    Fan is an air pushing device. Either Axial or Centrifugal type systems are used to move the air in low pressure. It is rotated by a motor separately.
When the fan is a housing of blades and motor, then it called as Blower. It directs the air in a single path with high pressure.
2.          What is Heat Rate of Power Plant?
Ans.     Heat rate is a measure of the turbine efficiency. It is determined from the total energy input supplied to the Turbine divided by the electrical energy output
3.          What is Hydrodynamic Cavitation?
Ans.    Hydrodynamic cavitation describes the process of vaporization in a constrained channel at a specific velocity.
Bubble generation and Bubble implosion which occurs in a flowing liquid as a result of a decrease and subsequent increase in pressure.
4.          What is Difference between Hardness and Toughness?
Ans.    Toughness is the ability of a material to absorb energy.
Hardness is the ability of a material to withstand wear.
5.          What is the hottest part of Refrigerant in Refrigeration?
Ans.     Compressor
6.          What does F.O.F Stand for Piping Design?
Ans.     Face of Flange, The F.O.F (Raised face and Flat face) is used to know the accurate dimension of the flange in order to avoid the minute errors in measurement in case of vertical or horizontal pipe lines.
7.          Where Multi stage Pump is Used?
Ans.     Pressure washing of Aircraft, Trains, Boats and Road vehicles as well as Spray washing of industrial parts and Electronic components.
8.          What does pump develop:- (a) Flow   (b) Pressure
Ans.     A pump does not create pressure, it only creates flow. Pressure is a measurement of the resistance to flow.
9.          How to measure temperature of Bearing?
Ans.    Normally the temperature range from 80 degree to 110 degree Celsius. So the following temperature measurement devices are used.
· Dial Type Bearing Temperature Detector
· Stator Winding Temperature Detector
· Resistance Bearing Temperature Detector (Bearing RTD)
· Specialized in Pin type RTD
10.          Difference between Performance and Efficiency?
Ans.    The accomplishment of a given task measured against preset known standards of accuracy, completeness, cost, and speed is called as Performance.
Efficiency is defined as the input given and the work obtained from that input like money, time, labour etc. It’s the main factor of productivity.