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Showing posts with label GATE 2016. Show all posts
Showing posts with label GATE 2016. Show all posts

GATE Mechanical Engineering Preparation and free study material

Normally GATE exam consists of those questions which are mostly related to research to be done at Master Level i.e. M.Tech or M. E. level. So, It is very necessary to get ready for preparation of those subjects on which complete M. Tech or M. E. is based. In case of Mechanical Engineering, One should prepare the following most important subjects.

1. Mechanics of Solids or (Engineering Mechanics + Strength of Materials) which is base for any motion and design related research.

2. Thermal engineering which includes Fluid Mechanics which is most important subject for thermal engineering specialization in M. Tech or M. E. Second is thermodynamics, Heat and mass transfer and Refrigeration and Air conditioning. One can find numerous application of fluid mechanics like fountains, fire brigade works, hydro-power station and many more.

All you need to know about Thermodynamics Properties

Thermodynamic Property is a measurable characteristic of the system. To get the status of any process of the system, one should have at least two properties at hand. Thus to define the state of a system, we must know the information about different thermodynamics properties. 

One can classify the properties in following ways.

1. Primitive Properties (which are taken from other branches of the science)
  • Pressure, P
  • Velocity, v
  • Volume, V

2. Basic Thermodynamic Properties (which are defined by the laws of the thermodynamics)
  • Temperature, T (defined by the zeroth law of the Thermodynamics)
  • Internal Energy, U (defined by the first law of the Thermodynamics)
  • Entropy, S (defined by the second law of the Thermodynamics)
3. Derived Thermodynamics Properties (Combination of various other properties defined earlier)
  • Enthalpy ( U + P.V)
  • Gibbs Energy (U + PV-TS)
  • Specific Heat at Constant Pressure, Cp
  • Specific Heat at Constant Volume, Cv

Difference between 'Thermodynamics' and 'Heat Transfer'

Thermodynamics and Heat Transfer both are part of thermal engineering and each has its own meaning and importance. Both deals with heat and energy then, one might ask, what is the real difference between the two subjects ? i.e. Thermodynamics and Heat Transfer

"Thermodynamics" deals with the amount of energy in form of heat or work during a process and only considers the end states in equilibrium. It will not give information about how long it will take to reach to the final state in equilibrium. While,

"Heat Transfer" deals with the rate of energy transfer thus, it gives idea of how long a heat transfer will occur? Heat transfer deals with time and non equilibrium phenomena. Heat can only transfer when there is a temperature gradient exists in a body and which is indication of non equilibrium phenomena.

In short, Thermodynamics gives "Why"  a process will occur and Heat Transfer will tell, "How" a process will occur when there is a concern about transfer of heat.

To support all these arguments, Thermodynamics uses following laws,

  • Zeroth Law of Thermodynamics
  • First law of Thermodynamics
  • Second Law of Thermodynamics
  • Third Law of Thermodynamics

While, Heat Transfer uses,

  • Fourier's Law (Heat conduction)
  • Newtons Law of Cooling (Heat convection)
  • Planck's Law (Thermal Radiation)
  • Stephan Boltzman's Law (Thermal Radiation)
  • Wein's Law (Thermal Radiation)
  • Kirchoff's Law (Thermal Radiation)
  • Lambart's Law (Thermal Radiation)
Learn more about such important questions to be asked in Mechanical Engineering Interview

Most important subjects for GATE Mechanical Engineering

Normally in Mechanical engineering, we learn different subjects covering complete mechanical engineering and its basics.

Undergraduate syllabus or curriculum normally contains subjects like
Machine Design mainly requires knowledge of Strength of Materials because to design of any machine component, we need to look for types of loading, calculation of equivalent forces and stresses. So, before studying Machine Design, we need to have sound knowledge of strength of materials. So, in curriculum of any mechanical engineering, Strength of Materials/Mechanics of Solids are covered (in first or second semester) before Machine Design.

Objective questions in mechanical engineering (Thermal Engineering) for competitive exams

Choose the right answer:

1. One metre (1 m) of water column  is equivalent to 
(A) 0.1 kN per square meter
(B) 1.0 kN per square meter
(C) 10 kN per square meter
(D) 100 kN per square meter

Objective questions in mechanical engineering (Manufacturing) for competitive exams

Choose the correct answer:

1. In a tool steel the percentage of silicon is usually restricted to 
(A) 0.5 % 
(B) 1 %
(C) 0.2 %
(D) 2 %