Home
About Us
Contact Us
Privacy Policy
Search
Home
→
Chemical Heat Transfer
→
In case of surface condensers, a straight line is obtained on plotting 1/U vs. ____________ on an ordinary graph paper?
Related MCQs
Viscosity of gases __________ with increase in temperature?
During crystallisation, formation of crystal can occur in __________ solution only?
When does the heat generated by fluid friction becomes appreciable compared to the heat transferred between the fluids ?
Condensing film co-efficient for steam on horizontal tubes ranges from 5000 to 15000 Kcal/hr.m2.°C. Condensation of vapor is carried out inside the tube in a shell and tube heat exchanger, when the__________?
A cube, sphere & a thin circular plate (all having same mass and made of same material) are all heated to 300°C and allowed to cool in natural air. Which one will cool the slowest ?
A steel sphere of radius 0.1 m at 400°K is immersed in an oil at 300°K. If the centre of the sphere reaches 350°K in 20 minutes, how long will it take for a 0.05 m radius steel sphere to reach the same temperature (at the centre) under identical conditions? Assume that the conductive heat transfer co-efficient is infinitely large ?
Presence of a non-condensing gas in a condensing vapour__________?
The critical radius of insulation for cylindrical pipe is (where, hi = heat transfer coefficient at inside of the pipe) ?
A process stream of dilute aqueous solution flowing at the rate of10 Kg.s-1 is to be heated. Steam condensate at 95°C is available for heating purpose, also at a rate of 10 Kg.s-1. A 1 – 1 shell and tube heat exchanger is available. The best arrangement is__________?
Natural convection is characterised by__________?
The unit of heat transfer co-efficient is__________?
In Joule’s experiment, an insulated container contains 20 kg of water initially at 25°C. It is stirred by an agitator, which is made to turn by a slowly falling body weighing 40 kg through a height of 4 m. The process is repeated 500 times. The acceleration due to gravity is 9.8 ms-2. Neglecting the heat capacity of agitator, the temperature of water (in °C) is__________?
Multiple effect evaporators are commonly used in the manufacture of P. Paper Q. Superphosphate R. Sugar S. Fats ?
Air is to be heated by condensing steam. Two heat exchangers are available (i) a shell and tube heat exchanger and (ii) a finned tube heat exchanger. Tube side heat transfer area are equal in both the cases. The recommended arrangement is__________?
Heat exchanger tubes are never made of__________?
The variation of thermal conductivity of a metal with temperature is often correlated using an expression of the form K = K0 + at, where, K is the thermal conductivity and T is the temperature (in °K). The units of ‘a’ in SI system will be__________?
Colburn analogy is applicable for the value of Prandtl number from__________?
For what value of Prandtl number, the Col-burn analogy is valid ?
The thermal efficiency of a reversible heat engine operating between two given thermal reservoirs is 0.4. The device is used either as a refrigerator or as a heat pump between the same reservoirs. Then the coefficient of performance as a refrigerator (COP)R and the co-efficient of performance as a heat pump (COP)HP are __________?
Heat transfer rate per unit area is called__________?
Tube pitch is the __________ of tube diameters and the clearances?
A black body when hot, emits heat radiation of __________ wavelengths?
With increase in temperature, the thermal conductivity of non-metallic amorphous solids__________?
Which of the following parameters is increased by use of finned tube in a multipass shell and tube heat exchanger ?
Value of Nusselt number [Nu = (hD/k)] for the heat transfer by conduction from a droplet or a spherical particle to a surrounding stagnant film is__________?
The main purpose of providing fins on heat transfer surface is to increase the__________?
When vaporisation takes place through a blanketting film of gas, the phenomenon is termed as __________ boiling?
The left face of a one dimensional slab of thickness 0.2 m is maintained at 80°C and the right face is exposed to air at 30°C. The thermal conductivity of the slab is 1.2 W/m.K and the heat transfer co-efficient from the right face is 10 W/m2.K. At steady state, the temperature of the right face in °C is__________?
Agitated film evaporator is suitable for concentrating __________ liquids?
Kirchoff’s law is applicable to__________?
The Dittus-Boelter equation for convective heat transfer [(i.e. h = 0.023 (K/D) (Re)0.8 (Pr)0.4] cannot be used for__________?
The radiation heat flux from a heating element at a temperature of 800°C, in a furnace maintained at 300°C is 8 kW/m2. The flux, when the element temperature is increased to 1000°C for the same furnace temperature is__________?
A composite flat wall of a furnace is made of two materials ‘A’ and ‘B’. The thermal conductivity of ‘A’ is twice of that of material ‘B’, while the thickness of layer of ‘A’ is half that of B. If the temperature at the two sides of the wall are 400 and 1200°K, then the temperature drop (in °K) across the layer of material ‘A’ is__________?
In forced convection, the heat transfer depends on __________?
Kg of liquid evaporated per hour in an evaporator is defined as its__________?
In SI units, fouling factor is expressed in __________?
Radiation heat losses from satisfactorily insulated high pressure boiler may be about __________ percent?
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__________?
In case of surface condensers, a straight line is obtained on plotting 1/U vs. ____________ on an ordinary graph paper?
A. 1/V̅ -0.8
B. V̅ -0.8
C. V̅ -2
D. 1/ V̅ -2
Correct Answer:
1/V̅ -0.8
✔
Last Updated:
March 03, 2019