MCQ: HEAT TRANSFER-1        Dimensionless num HT        HT Symbols-2         HT Symbols-1           MCQ HT-2            PTU HT Paper Sol B             PTU HT Paper Sol A            Fin HT


Mcq on heat transfer help in clear and deep understanding of the subject. Thus, more mcq should be learnt to further increase the knowledge.

  1. Law for the monochromatic radiation emissive power is

(a) Stephen’s Boltzmann Law

(b) Planck’s Law

(c) Wien’s displacement Law


ANS: (b)

  1. Radiosity is defined as
  • (a) Total reflected radiations
  • (b) Total emitted radiations
  • (c) Difference of emitted and reflected radiations
  • (d) None
  • ANS: (b)
  1. Absorbtivity is zero for an opaque
  • (a) Black body
  • (b) White Body
  • (c) Grey body
  • (d) None
  • ANS: (b)
  1. As per Kirchoff’s law
  • (a) Radiosity = absorbtivity
  • (b) Reflectivity = absorbtivity
  • (c) Emissivity= absorbtivity
  • (d) None
  • ANS: (c)
  1. Free convection deals with
  • (a) Re and Pr
  • (b) Gr and Re
  • (c) Nu and Re
  • (d) None
  • ANS: (d)
  1. Thermal boundary layer is bigger than the hydrodynamic boundary layer when
  • (a) Pr >>1
  • (b) Pr=1
  • (c) Pr <<1
  • (d) None
  • ANS: (c)
  1. Free Convective heat transfer coefficient is
  • (a) Greater than h for forced convection
  • (b) Equal to h for forced convection
  • (c) Less than h for forced convection
  • (d) None
  • ANS: (c)
  1. Reynolds number = 5 x 105
  • (a) Where laminar flow starts
  • (b) Where laminar flow ends
  • (c) Where turbulent flow starts
  • (d) None
  • ANS: (b)
  1. Rate of heat transfer is
  • (a) More in drop-wise than  film-wise condensation
  • (b) Equal in drop-wise and film-wise condensation
  • (c) Less in drop-wise than film-wise condensation
  • (d) None
  • ANS: (a)
  1. Critical heat flux in pool boiling lies in
  • (a) First regime
  • (b) Second regime
  • (c) Third regime
  • (d) None
  • ANS: (c)
  1. Rate of heat transfer will be
  • (a) More in pool boiling than in flow boiling
  • (b) More in flow boiling than in Pool boiling
  • (c) Equal in pool and flow boiling
  • (d) None
  • ANS: (b)
  1. Boiling and condensation temperatures for water are
  • (a) Equal
  • (b) Greater in boiling
  • (c) Less in boiling
  • (d) None
  • ANS: (a)
  1. The units of overall heat transfer coefficient are
  • (a) W/m0C
  • (b) W/m2 0C
  • (c) W/s m 0C
  • (d) None
  • ANS:(b)
  1. Overall heat transfer coefficient accounts for
  • (a) Only conduction and convection
  • (b) Radiation and conduction
  • (c) Radiation and convection
  • (d) None
  • ANS: (d)
  1. Reynolds number is the ratio of
  • (a) Inertia force/gravitational force
  • (b) Viscous force/inertia force
  • (c) Buoyancy force/viscous force
  • (d) None
  • ANS: (d)
  1. Product of Grashoff’s and Prandtl number is used in
  • (a) Forced convection
  • (b) Free convection
  • (c) Free as well as in forced convection
  • (d) None
  • ANS: (b)
  1. Critical radius of insulation for a wire will be
  • (a) 2k/h0
  • (b) 3k/ h0
  • (c) k/ h0
  • (d) None
  • ANS:(c)
  1. Thermal conductivity is rate of heat transfer
  • (a) Per unit area/per unit temperature/per unit wall thickness
  • (b) Per unit area /per unit wall thickness
  • (c) Per unit area/per unit temperature difference/per unit wall thickness
  • (d) None
  • ANS:(c)
  1. Thermal diffusivity is the ratio of
  • (a) Thermal conductivity and kinematic viscosity
  • (b) Thermal conductivity and Biot number
  • (c) Thermal conductivity and temperature gradient
  • (d) None
  • ANS:(d)
  1. During free convection , motion is caused by
  • (a) Pump in case of a liquid
  • (b) A blower in case of a gas
  • (c) Buoyancy force
  • (d) None
  • ANS: (c)