reduction in thermal resistance during heat transfer does not occur in the (A) Convection heat transfer by stirring the fluid and cleaning the heating surface (B) Conduction heat transfer by reduction in the material thickness and increase in the thermal conductivity (C) Radiation heat transfer by increasing the temperature and reducing the emissivity (D) None of these

reduction in thermal resistance during heat transfer does not occur
in the
(A) Convection heat transfer by stirring the fluid and cleaning the heating
surface
(B) Conduction heat transfer by reduction in the material thickness and
increase in the thermal conductivity
(C) Radiation heat transfer by increasing the temperature and reducing the
emissivity
(D) None of these
by

1 Answer

Answer :

Option C
by

Related questions

Pick out the correct statement. (A) 1 kcal/hr.m.°C is equal to 1 BTU/hr. ft.°F (B) In steady state heat conduction, the only property of the substance which determines the temperature distribution, is the thermal conductivity (C) In unsteady state heat conduction, heat flows in the direction of temperature rise (D) In heat transfer by forced convection, Grashoff number is very important

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Last Answer : (B) In steady state heat conduction, the only property of the substance which determines the temperature distribution, is the thermal conductivity

In a furnace with heating element temperature at 1700°C, the dominant mechanism of heat transfer will be (A) Conduction (B) Radiation (C) Natural convection (D) Forced convection

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Last Answer : (B) Radiation

The heat transfer by radiation from a mild steel surface is to be reduced by reducing the emissivity of the surface. This can be best achieved by (A) Painting the surface black (B) Painting the surface white (with aluminium paint) (C) Giving the surface a mirror finish (D) Roughening the surface

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Mode of heat transfer in which the fluid moves under the influence of changes in fluid pressure produced by external work is called (A) Radiation (B) Natural convection (C) Forced convection (D) Conduction

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Walls of a cubical oven are of thickness l, and they are made of material of thermal conductivity k. The temperature inside the oven is 100°C and the inside heat transfer co-efficient is ‘3k/l’. If the wall temperature on the outside is held at 25°C, what is the inside wall temperature in degree centigrade?(A) 35.5 (B) 43.75 (C) 81.25 (D) 48.25

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Pick out the wrong statement. (A) Reciprocal of the resistance to heat flow is called thermal conductance (B) Unit of thermal conductance is W/°K (C) Thermal conductance of a wall of thickness 'L', thermal conductivity 'k' and heat flow area 'A' is kL/A (D) None of these

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Last Answer : (2) Convection Explanation: The process of heat transfer from one place to another place without the movement of particles is called conduction,

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Last Answer : Convection

Which of the following is the formula for thermal resistance?  A. Thickness of material/ thermal conductivity of material  B. 2(thickness of material)/thermal conductivity of material  C. Thickness of material/ 2(thermal conductivity of material)  D. Thickness of material x thermal conductivity of material

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Last Answer : Thickness of material/ thermal conductivity of material