A. 1
B. 7
C. 18
D. 26
Correct Answer: 7 ✔
Last Updated: March 03, 2019
Related MCQs
- In the free convection regime of pool boiling, the heat flux is proportional to__________?
- Prandtl number is the ratio of__________?
- Prandtl number is given by__________?
- Trap is used to remove __________ from steam pipe lines?
- Wavelength corresponding to the maximum energy is inversely proportional to the absolute temperature. This is __________ law?
- Economy of a multiple effect evaporator depends upon the __________?
- A wall has two layers of materials A and B; each made of a different material. Both the layers have the same thickness. The thermal conductivity of material A is twice that of B. Under the equilibrium, the temperature difference across the wall is 36°C. The temperature difference across the layer A is __________ °C?
- Temperature profile in steady state heat transfer is__________?
- Maximum water velocity in tubes of a 1-2 shell and tube heat exchanger may be around __________ metres/second?
- A tank painted with which of the following coloured paints, would heat up maximum by radiation from sun ?
- Three materials A, B and C of equal thickness and of thermal conductivity of 20, 40 & 60 kcal/hr. m. °C respectively are joined together. The temperature outside of A and C are 30°C and 100°C respectively. The interface between B and C will be at a temperature of __________ °C?
- The thermal radiation emitted by a body is proportional to Tn, where T is its absolute temperature. The value of ‘n’ is exactly 4 for__________?
- Evaporation by thermo compression results in the __________?
- Use of transverse baffles in a shell and tube heat exchanger is done to increase the__________?
- Which of the following situations can be approximated to a steady state heat transfer system ?
- Heat transfer by __________ may not necessarily require the presence of a medium?
- Nusselt number is the ratio of the __________?
- Prandtl number is the reciprocal of__________?
- For a multipass shell and tube heat exchanger, the LMTD correction factor is always__________?
- Thermal conductivity of a gas at low density, __________ with increase in temperature ?
- The interchange factor for radiation heat transfer from surface ‘x’ to surface ‘y’ in case of an infinite parallel planes with emissivities εx & εy is given by__________?
- With increase in temperature, the thermal conductivity of a gas __________?
- Which area is used in case of heat flow by conduction through a cylinder ?
- The rate of emission of radiation by a body does not depend upon the__________?
- In a cooling tower, water becomes cool by__________?
- Out of the following four assumptions used in the derivation of the equation for LMTD [LMTD = (Δt1 – Δt2)/ln(Δt1/Δt2)], which one is subject to the largest deviation in practice ?
- What is the logarithmic mean of r1 and r2 ?
- The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe, where the wall heat flux is constant, is__________?
- The overall resistance for heat transfer through a series of flat resistance, is the __________ of the resistances?
- Heat transfer co-efficient equation for forced convection, Nu = 0.023 Re 0.8. Pr n, is not valid, if the value of __________?
- An ejector is used to__________?
- In a laboratory test run, the rate of drying was found to be 0.5 x 10-3 kg/m2.s, when the moisture content reduced from 0.4 to 0.1 on dry basis. The critical moisture content of the material is 0.08 on a dry basis. A tray dryer is used to dry 100 kg (dry basis) of the same material under identical conditions. The surface area of the material is 0.04 m2/kg of dry solid. The time required (in seconds) to reduce the moisture content of the solids from 0.3 to 0.2 (dry basis) is__________?
- Peclet number (Pe) is given by__________?
- In Fourier’s law, the proportionality constant is called the__________?
- When the ratio of the Grashoff number and to the square of Reynolds number is one, the dominant mechanism of heat transfer is __________?
- The units of resistance to heat transfer is __________?
- For hot feed, forward feeding as compared to backward feeding results in __________ economy?
- In sub-cooled boiling ?
- Heat transfer by conduction results due to the transfer of free electrons, kinetic energy & vibrational energy from one molecule to another. Conduction heat transfer cannot take place__________?
- The thickness of condensate layer in filmwise condensation depends on the__________?
- The heat transfer co-efficient in film type condensation is __________ that for dropwise condensation?
- Steam economy in case of a triple effect evaporator will be __________?
- In a forward feed multiple effect evaporator unit__________?
- Dropwise condensation is promoted on a/an __________ surface?
- Which of the following parameters of the fluid is not very important, while deciding its route in a shell and tube heat exchanger ?
- It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of vaporisation is 2100 kJ/kg and the specific heat of the solution is 4 kJ/kg.K. The rate at which the heat has to be supplied in (kJ/min) to the evaporator is__________?
- Fqra cold viscous feed, backward feed gives __________ than forward feed?
- The Graetz number is concerned with the__________
- The unit of conductance in SI unit is__________?
- Which of the following has the lowest Prandtl number ?
- In case of a multipass shell and tube heat exchanger, the temperature drop in the fluid __________?