CAT-Common Admission Test – Mechanical Engineering Interview question and answer ,Basics of mechanical Engineering, Important topics in mechanical Engineering

Basics of thermodynamics, such as air cycle, laws, curves, Hydraulic machines, types of turbines, pumps, indicator diagrams etc. automobiles and engines (just basic). Theory of machines , basic mechanisms, gyroscopes, flywheels, governor, differentials, gears, etc… material science, Fe diagram, hardening, heat treatment, etc… manufacturing processes. Elective.

1.What is mechanical engineering?
Mechanical engineering is a discipline of engineering that applies the principles of physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the production and usage of heat and mechanical power for the design, production, and operation of machines and tools

2.Explain mechatronics?
Mechatronics refers to the efficient and effective integration of mechanical systems and electronics. It is a blend of mechanics and electronics, and has come to mean the synergistic use of:

precision engineering
control theory
computer science
mathematics
sensor technology, to design enhanced or “smart” products, processes and systems.

3. what are Carnot cycle, Otto cycle, and Diesel cycle?
Carnot cycle – Represents most efficient cycle that operates between two fixed temperatures TH and TL
Otto Cycle – Represents ideal cycle for spark-ignition (SI) engines. Ex: Processes in 4-stroke engine cycle
Diesel cycle – Represents ideal compression ignition (CI) engine. Almost similar to Otto cycle

4.Explain simple vapour compression cycle in refrigerator?
Compression refrigeration cycles in general take advantage of the idea that highly compressed fluids at one temperature will tend to get colder when they are allowed to expand. If the pressure change is high enough, then the compressed gas will be hotter than our source of cooling (outside air, for instance) and the expanded gas will be cooler than our desired cold temperature. In this case, we can use it to cool at a low temperature and reject the heat to a high temperature.

Vapor-compression refrigeration cycles specifically have two additional advantages. First, they exploit the large thermal energy required to change a liquid to a vapor so we can remove lots of heat out of our air-conditioned space. Second, the isothermal nature of the vaporization allows extraction of heat without raising the temperature of the working fluid to the temperature of whatever is being cooled.

5.Which compression is usually used in a/c?
Hermetically sealed reciprocating compressor .

Why don’t CI engine need a spark?
The compression ratio is high enough to combust the diesel without the aid of sparkplugs

What is MPFI, TPFC system?
What are the law of thermodynamics and PMMs?
Which is your favourite car and why?
What is your favourite two-wheeler and why?
During intial start-up,exhaust smoke appears white. why?
What are the common automobile specification?
Define heat exchangers?
Explain concept of black body?
Describe the lubrication system in IC engines?
Can poisson’s ratio be negative?
What is bending moment equation and torque equation?
What is crippling load and its equations?
What are principal stresses and strains?
What is Endurance limit?
Draft tube and its application?
What is six sigma?
Where does the future of mechanical engineering lie?
Differentiate between absolute and kinematics viscosity?
What is magnus efect?
Compare the constrctional details of a petrol and diesel engine?
Which gear is used to obtain maximum speed ratio?