Articles Posted in the " Heat Transfer " Category


  • MCQ ON RADIATION EXCHANGE BETWEEN SURFACES

    MCQ ON RADIATION EXCHANGE BETWEEN SURFACES

      MCQ ON RADIATION EXCHANGE BETWEEN SURFACES Shape factor F12 between two bodies depends on the (a) Shape and size of the two bodies (b) Shape and size of the bigger body (c) Shape, size and orientation of the bigger body (d) None ANS:(d) Shape factor F12 between two bodies depends on the (a) Shape […]


  • HEAT TRANSFER FOR READY REFERENCE FOR AN UNIVERSITY EXAMINATION—–SHEET 3

    HEAT TRANSFER FOR READY REFERENCE FOR AN UNIVERSITY EXAMINATION—–SHEET 3

    HEAT TRANSFER FOR READY REFERENCE FOR AN UNIVERSITY EXAMINATION—–SHEET 3   25 Stefan’s Boltzmann Law Gives TOTAL emissive power of a black body. Etotal    T4   .        T is absolute temp Etotal Etotal =σ T4 W/m2 26 WIEN’S DISPLACEMENT LAW The wavelength for maximum emissive power decreases with increase in absolute temperature λmaxT =2898 λmaxT […]


  • HEAT TRANSFER FOR READY REFERENCE FOR AN UNIVERSITY EXAMINATION—SHEET 2

    HEAT TRANSFER FOR READY REFERENCE FOR AN UNIVERSITY EXAMINATION—SHEET 2

    HEAT TRANSFER FOR READY REFERENCE FOR AN UNIVERSITY EXAMINATION—SHEET 2   11. FREE OR NATURAL CONVECTION   When bulk motion of the fluid is caused by the density difference or Buoyancy force, it is called Free or Natural convection. It is governed by the product of Grashoff’s number and Prandtl number. All the convection processes […]


  • HEAT TRANSFER FOR READY REFERENCE FOR UNIVERSITY EXAMINATION—–SHEET 1

    HEAT TRANSFER FOR READY REFERENCE FOR UNIVERSITY EXAMINATION—–SHEET 1

    HEAT TRANSFER FOR READY REFERENCE FOR UNIVERSITY EXAMINATION—–SHEET 1   HEAT TRANSFER BRIEF NOTES FOR THE FINAL EXAMINATION   DIFFERENCE BETWEEN THERMODYNAMICS AND HEAT TRANSFER Sr. No. Thermodynamics HEAT TRANSFER          i. How much is the heat supplied and how much is the work done Tells rate of heat transfer  and               Tells the mode of […]


  • MCQ ON RADIATION HEAT TRANSFER

    MCQ ON RADIATION HEAT TRANSFER

    MCQ ON RADIATION HEAT TRANSFER   Plank’s law gives the radiation flux for a (a) A single wavelength (b)  Two wavelengths  ( c) Three wavelengths (d) None ANS: (a) Plank’s law gives the radiation flux for a (a) A Black body (b)  A Grey body  ( c) All types of bodies (d) None ANS: (a) Stefan’s Boltzmann […]


  • HEAT TRANSFER MCQ-RADIATION, CONVECTION, BOILING—

    HEAT TRANSFER MCQ-RADIATION, CONVECTION, BOILING—

    HEAT TRANSFER MCQ-RADIATION, CONVECTION, BOILING— Law for the monochromatic radiation emissive power is (a) Stephen’s Boltzmann Law (b) Planck’s Law (c) Wien’s displacement Law (d)None ANS: (b) Radiosity is defined as (a) Total reflected radiations (b) Total emitted radiations (c) Difference of emitted and reflected radiations (d) None ANS: (b) Absorbtivity is zero for an opaque […]


  • HEAT TRANSFER—M C Q on Radiation, Convection and Boiling

    HEAT TRANSFER—M C Q on Radiation, Convection and Boiling

    HEAT TRANSFER—M C Q on Radiation, Convection and Boiling Which Law gives the monochromatic emissive power? (a) Stefan’s Boltzmann Law (b) Kirchoff’s Law (c) Wien’s Displacement Law (d) None ANS: (d) All types of radiations are emitted from a body at (a) Room temperature (b) Boiling temperature of water (c) Melting temperature of steel (d) None ANS: (d) Radiations are more harmful with […]


  • HEAT TRANSFER PTU PAPER SOLUTION—–SECTION–B

    HEAT TRANSFER PTU PAPER SOLUTION—–SECTION–B

    HEAT TRANSFER PTU PAPER SOLUTION—–SECTION–B SECTION-B  Q2. Explain different phases of flow boiling. ANS: Flow boiling is much more complex than nucleate boiling. Here it will be a two phase heat transfer. Consider a vertical tube as shown in figure. Sub-cooled liquid is entering from below. As it moves upwards, getting heat from the tube […]