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 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 Mechanical Engineering Question Bank Based on P T U Paper Pattern —CONVECTION CONVECTION 1 MARK OBJECTIVE QUESTIONS Convective heat transfer takes place between Two solid surfaces in physical contact Between a solid surface and a fluid Between two fluids None Ans: (b) Select the correct formula for the convective rate of heat transfer […]
*HEAT TRANSFER MECHANICAL ENGINEERING Short Interview Question Answers on Conduction and Convection Heat Transfer—-Biot Number, Convective heat transfer coefficient, Numerical data on ‘h’, Mean film temperature, Difference between natural and forced convection, Q . Define Biot number and its significance. Biot number is Bi= conductive resistance/convective resistance = hLc/ksolid Where h is convective heat transfer […]
*HEAT TRANSFER MECHANICAL ENGINEERING Short Interview Question Answers on Conduction and Convection Heat Transfer—-Critical thickness of insulation, temperature distributions for a plane wall, cylinder and a sphere, temperature gradient, velocity gradient and pressure gradient, factors effecting thermal conductivity of a material, factors thermal conductivity of gases depend, Differentiate Nusselt number and Biot number, Grashoff’s number and […]
*HEAT TRANSFER MECHANICAL ENGINEERING Heat Exchangers–2—U—Overall heat transfer Coefficient DEFINITION OF OVERALL HEAT TRANSFER COEFFICIENT ‘U’ Overall heat transfer coefficient for conduction and convection taking place simultaneously.Its units are W/m2 K. 1/UA =1/hiAi+fi + ln (r2/r1)/2πkL +1/hoAo + fo Where fi and fo are fouling resistances on the inner and outer surfaces. CALCULATION OF U (i) On the basis […]
*HEAT TRANSFER MECHANICAL ENGINEERING Short Interview Question Answers on Heat Transfer—-Four Practical applications of each conduction, convection, radiation and expression for thermal resistance of a single wall, composite wall, single cylinder, composite cylinder, a single sphere and a composite sphere List four practical examples each for conduction, convection and radiation. Examples of conduction (i) The outside […]
Introduction to Free and Forced Convection Heat Transfer—-Definition of convection, free and forced convection, DERIVATION OF NUSSELT NUMBER EXPRESSION FOR BOTH FREE AND FORCED CONVECTION, Dimensionless numbers for free convection, Dimensionless numbers for forced convection, METHODS FOR THE ANALYSIS OF CONVECTION and Newton’s Law of Viscosity, difference between laminar and turbulent flow CONVECTION HEAT TRANSFER It takes place in fluids (liquids, […]
Empirical Correlations for Free and Forced Convection Free Convection TABLE: (i) CRITERIA FOR LAMINAR FLOW & TURBULENT FLOW IN FREE CONVECTION (ii) THE IMPERRICAL CORRELATION in Free Convection Free Convection Laminar condition Turbulent condition Over a horizontal flat plate with hot surface upwards Gr Pr […]
Short Interview Question Answers on Modes of Heat Transfer—-Difference between heat transfer and thermodynamics, Definition of conduction, convection , radiation, Fourier Number, Internal Energy Generation, Nusselt Number and Biot Number Q. How heat transfer is different from thermodynamics? Heat is always in motion or transition. It can also find the temperature distribution. It also tells mode […]