pKmcqsquiz

Pagination on API result
Question: Pick out the wrong statement ?
  • 1. With change in temperature, the radiant energy emitted by a black body remains unchanged
  • 2. Absorptivity of a body approaches unity in case of diffuse reflection
  • 3. Absorptivity of a perfectly black body is unity
  • 4. Value of Stefan-Boltzmann constant is 4.876 × 10-8 KCal/m2.hr.°K4
Question: Choose the correct equation ?
  • 1. Nu = (Re) (Pr) (Gz)
  • 2. Nu = (Re) (Pr) (St)
  • 3. Nu = (Re) (Pr)
  • 4. Nu = (Pr) (St)
Question: Pick out the wrong statement ?
  • 1. Economy of a multiple effect evaporator is not influenced by the boiling point elevation
  • 2. Two identical cubes of iron and copper will have the same heat content under the sameconditions of temperature
  • 3. Double pipe heat exchangers are mostly used in the field of refrigeration
  • 4. Finned tube heat exchangers are suitable for heating air by steam
Question: Pick out the correct equation ?
  • 1. jH = (St)(Pr)2/3 = f/2
  • 2. jH = (St)(Pr)1/3 = f/2
  • 3. jH = (St)2/3(Pr) = f/2
  • 4. jH = (St)1/3(Pr) = f/2
Question: Pick out the wrong statement:
  • 1. The emissivity of a surface decreases, if it gets corroded by atmospheric environment
  • 2. The emissivity of a surface increases with increase in surface roughness
  • 3. The emissivity of a polished surface is quite low
  • 4. The emissivity of a non-metallic surface decreases with increase in the temperature
Question: Pick out the wrong statement ?
  • 1. In drying a solid containing moisture above the critical moisture content the number of degrees of freedom is 2
  • 2. Sherwood number in mass transfer corresponds to Nusselt number in heat transfer and Schmidt number to Prandtl number
  • 3. Forced convection is relatively more effective in increasing the rate of mass transfer, if Schmidt number is larger
  • 4. Hot gases at moderate pressure are usually in the shell side of shell and tube heat exchangers. At higher pressure, however, it is customary to put gas in the tube side
Question: Pick out the wrong statement?
  • 1. Bubble size increases with the dynamic viscosity of the liquid in case of nucleate pool boiling
  • 2. Thermal conductivity of a dry material is more than that of the damp material
  • 3. Ratio of its capacity to economy equals the steam consumption in kg/hr in an evaporator
  • 4. Vaporisation of organic substances in evaporator mostly causes foam formation
Question: Pick out the wrong statement?
  • 1. Fluid movement under the influence of buoyant forces resulting from change in density takes place in case of natural convection
  • 2. The ratio NNu/NRe . Npr is called the Stanton number
  • 3. The Peclet number is a measure of the ratio of energy transport by convection to that by conduction
  • 4. The Colburn jH factor for heat transfer is given by Nst Npr
Question: Pick out the wrong statement ?
  • 1. Heat transfer from a hot body to cold body by the emission of heat waves is called radiation
  • 2. Filmwise condensation takes place on non-wettable surfaces
  • 3. The boiling point of a solution is affected by liquid head as well as boiling point elevation
  • 4. None of these
Question: Pick out the correct statement ?
  • 1. 1 kcal/hr.m.°C is equal to 1 BTU/hr. ft.°F
  • 2. In steady state heat conduction, the only property of the substance which determines the temperature distribution, is the thermal conductivity
  • 3. In unsteady state heat conduction, heat flows in the direction of temperature rise
  • 4. In heat transfer by forced convection, Grashoff number is very important

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