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  • PROJECTION OF POINTS

    PROJECTION OF POINTS

    PROJECTION OF POINTS  Which are the types of projections done in engineering drawing? A. Orthographic projections are done on HP, VP and PP planes. Since projections are done on a plane, these projections are 2 dimensional. Describe the position of points in the various quadrants and its projections with respect to the reference line xy. […]


  • Del operator-Laplacian operator-Divergence

    Del operator-Laplacian operator-Divergence

    Del operator-Laplacian operator-Divergence Del operator ∇ = (∂/∂x,  ∂/∂y, ∂/∂z) Gradient is partial derivative of a function with respect to x or y or z ∂p/∂x is pressure gradient in x direction ∂p/∂y is pressure gradient in y direction ∂p/∂z is pressure gradient in z direction ∂v/∂x,  ∂v/∂y, and ∂v/∂z are velocity gradients. ∂V/∂x,  ∂V/∂y […]


  • mcqs – Shear stresses in beams

    mcqs – Shear stresses in beams

    mcqs – Shear stresses in beams The direction of shear stress in a loaded beam is (a) Horizontal (b) Horizontal as well as vertical (c) Vertical (d) None (Ans: b) Shear stress in the beam acting on the cross section is (a) Normal to the cross section (b) Tangential to the cross section (c) Neither normal […]


  • Summary of Air conditioning

    Summary of Air conditioning

    Summary of Air conditioning DEFINITION OF AIR CONDITIONING It is a process of controlling simultaneously four parameters, temperature, humidity, purity and velocity of air in a closed space. Air conditioning is cooling in summer, heating in winter with ventilation. PRACTICAL APPLICATIONS Air conditioning is required for comfort, food preservation, for a better accuracy measuring instruments […]


  • Psychrometric chart

    Psychrometric chart

    Psychrometric chart  This chart contain moist air properties. Construction Refer Fig. is a Psychrometric chart.   Dry bulb temperature is the abscissa (along x-axis) and specific humidity is the ordinate (along y-axis) at 1 atmospheric pressure. It contains the following lines:Vertical lines for dry bulb temperature Horizontal lines towards right for specific humidity and towards […]


  • Psychrometry

    Psychrometry

    Psychrometry Definition Psychrometry is the study of the properties of moist air (dry air + water vapor). It includes the study of various temperatures, humidities and psychrometric processes. Dry Air It is a mixture of gases (mainly oxygen and nitrogen) which does not contain water vapor. Wet air Wet air or moist air is a […]


  • Steam tables and charts

    Steam tables and charts

    STEAM TABLES AND CHARTS Steam is in a vapor state which is widely different from a gas. No gas laws are applicable to vapor analysis. There are complex equations of state for a vapor. Consequently tables and charts have been prepared for the steam vapors for making analysis simple and time saving.  STEAM TABLES Only […]


  • Specific properties of water and steam

    Specific properties of water and steam

    Specific properties of water and steam Definition Specific properties are per kg. Examples are specific volume, specific enthalpy, specific entropy, specific internal energy and specific latent heat. Symbol These specific properties are represented by the small alphabet like v, h,s,u,cP etc. Reference temperature for the enthalpy and entropy of water is 00C. Enthalpy of water […]


  • Phase transformations

    Phase transformations

    PHASE TRANSFORMATION Phase transformation means change of ice to water and from water to steam. It takes place at constant temperature and at constant pressure respectively. SUB-COOLED ICE Ice at a temperature lower than its freezing temperature 00C is called sub-cooled ice. Hence ice at -60C, -130C, -290C will be sub-cooled ice. Consequently ice at -60C […]


  • Combustion in Internal Combustion engines

    Combustion in Internal Combustion engines

    Combustion in Internal Combustion engines  Definition Combustion is rapid burning of the air fuel mixture (carbon + Oxygen and hydrogen + oxygen) to liberate heat energy. This burning takes place differently in spark ignition engines and diesel engines.In petrol engines, combustion  takes place by igniting the compressed air fuel mixture by a spark produced by […]