In which mode of heat transfer, the Biot number is important? (A) Transient heat conduction (B) Natural convection (C) Forced convection (D) Radiation

In which mode of heat transfer, the Biot number is important?

(A) Transient heat conduction

(B) Natural convection

(C) Forced convection

(D) Radiation

by

1 Answer

Answer :

(A) Transient heat conduction

by

Related questions

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

Description : 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

Last Answer : (C) Forced convection

The Fourier number (defined as a.t/L 2 ) is used in the analysis of problem involving heat transfer by (A) Forced convection (B) Natural convection(C) Transient conduction(D) Steady state conduction

Description : The Fourier number (defined as a.t/L 2 ) is used in the analysis of problem involving heat transfer by (A) Forced convection (B) Natural convection (C) Transient conduction (D) Steady state conduction

Last Answer : (C) Transient conduction

View factor is important in heat transfer by (A) Steady state conduction (B) Natural convection (C) Forced convection (D) Radiation

Description : View factor is important in heat transfer by (A) Steady state conduction (B) Natural convection (C) Forced convection (D) Radiation

Last Answer : (D) Radiation

Mode of heat transfer involved in the cooling of air cooled internal combustion engine is (A) Conduction(B) Natural convection(C) Forced convection(D) None of these

Description : Mode of heat transfer involved in the cooling of air cooled internal combustion engine is (A) Conduction (B) Natural convection (C) Forced convection (D) None of these

Last Answer : (B) Natural convection

Heat transfer by __________ may not necessarily require the presence of a medium. (A) Conduction (B) Natural convection (C) Forced convection (D) Radiation

Description : Heat transfer by __________ may not necessarily require the presence of a medium. (A) Conduction (B) Natural convection (C) Forced convection (D) Radiation

Last Answer : (D) Radiation

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

Description : 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

Last Answer : (B) Radiation

If heat transfer rate varies with the time, it is termed as (A) Forced convection (B) Steady state conduction (C) Monochromatic radiation (D) None of these

Description : If heat transfer rate varies with the time, it is termed as (A) Forced convection (B) Steady state conduction (C) Monochromatic radiation (D) None of these

Last Answer : (D) None of these

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

Description : 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 ... in the direction of temperature rise (D) In heat transfer by forced convection, Grashoff number is very important

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

Nusselt number is a function of Prandtl number and __________ number of fluid in natural convection heat transfer. (A) Grashoff (B) Biot (C) Stanton

Description : Nusselt number is a function of Prandtl number and __________ number of fluid in natural convection heat transfer. (A) Grashoff (B) Biot (C) Stanton

Last Answer : (A) Grashoff

When the ratio of the Grashoff number and to the square of Reynolds number is one, the dominant mechanism of heat transfer is: (A) Free convection (B) Entry length problem in laminar forced conduction (developing thermal boundary layer) (C) Mixed convection (both free and forced) (D) Forced convection

Description : When the ratio of the Grashoff number and to the square of Reynolds number is one, the dominant mechanism of heat transfer is: (A) Free convection (B) Entry length problem in laminar forced ... (developing thermal boundary layer) (C) Mixed convection (both free and forced) (D) Forced convection

Last Answer : (C) Mixed convection (both free and forced)

Fourier's law applies to the heat transfer by (A) Convection (B) Radiation (C) Conduction (D) All (A), (B) & (C)

Description : Fourier's law applies to the heat transfer by (A) Convection (B) Radiation (C) Conduction (D) All (A), (B) & (C)

Last Answer : (C) Conduction

When warm and cold liquids are mixed, the heat transfer is mainly by (A) Conduction (B) Convection (C) Radiation (D) Both (A) & (C

Description : When warm and cold liquids are mixed, the heat transfer is mainly by (A) Conduction (B) Convection (C) Radiation (D) Both (A) & (C

Last Answer : (B) Convection

In furnaces operating at very high temperature (say) 1250°C, e.g. soaking pit), the maximum heat transfer takes place by (A) Conduction (B) Convection (C) Radiation (D) Cannot be predicted

Description : In furnaces operating at very high temperature (say) 1250°C, e.g. soaking pit), the maximum heat transfer takes place by (A) Conduction (B) Convection (C) Radiation (D) Cannot be predicted

Last Answer : (C) Radiation

Maximum heat transfer in high temperature furnaces is by (A) Conduction (B) Convection (C) Radiation (D) Either (A), (B) or (C); depends on the type of furnace

Description : Maximum heat transfer in high temperature furnaces is by (A) Conduction (B) Convection (C) Radiation (D) Either (A), (B) or (C); depends on the type of furnace

Last Answer : (C) Radiation

Gibbs phase rule finds application, when heat transfer occurs by (A) Conduction (B) Convection (C) Radiation (D) Condensation

Description : Gibbs phase rule finds application, when heat transfer occurs by (A) Conduction (B) Convection (C) Radiation (D) Condensation

Last Answer : (D) Condensation

Heat transfer by __________ is almost absent in case of fluidised bed drying operation. (A) Radiation (B) Conduction (C) Convection (D) Both (B) & (C)

Description : Heat transfer by __________ is almost absent in case of fluidised bed drying operation. (A) Radiation (B) Conduction (C) Convection (D) Both (B) & (C)

Last Answer : A) Radiation

Heat transfer to the water wall in a high pressure water wall type boiler furnace is mainly by (A) Conduction (B) Convection (C) Radiation (D) Both 'a' & 'b'

Description : Heat transfer to the water wall in a high pressure water wall type boiler furnace is mainly by (A) Conduction (B) Convection (C) Radiation (D) Both 'a' & 'b'

Last Answer : Option C

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

Description : 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 ... Radiation heat transfer by increasing the temperature and reducing the emissivity (D) None of these

Last Answer : Option C

In reverberatory furnace, charge is heated mainly by (A) Conduction (B) Natural convection (C) Radiation of heat from the roof of the combustion chamber (D) None of these

Description : In reverberatory furnace, charge is heated mainly by (A) Conduction (B) Natural convection (C) Radiation of heat from the roof of the combustion chamber (D) None of these

Last Answer : (C) Radiation of heat from the roof of the combustion chamber

Explain application of conduction and convection mode of heat transfer in automobile.

Description : Explain application of conduction and convection mode of heat transfer in automobile.

Last Answer : Applications of conduction1. Fins provided on motor cycle engine 2. Electric fuse cut off 3. Electric heater 4. Carbonisation of coal 5. Melting of iron in blast furnace 6. Fission reactions in ... 5. Radiator - Puts warm air out at the top and draws in cooler air at the bottom.

Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of- (1) Convection only (2) Conduction and convection only (3) Radiation and convection only (4) Convection, conduction and radiation

Description : Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of- (1) Convection only (2) Conduction and convection only (3) Radiation and convection only (4) Convection, conduction and radiation

Last Answer : (3) Radiation and convection only Explanation: Conduction is the transfer of heat energy by direct contact, convection is the movement of heat by actual motion of matter; radiation is the transfer of energy with the help of electromagnetic waves.

____ is the transfer of heat from one particle to another by contact. a. Conduction c. Radiation b. Convection d. Combustion

Description : ____ is the transfer of heat from one particle to another by contact. a. Conduction c. Radiation b. Convection d. Combustion

Last Answer : a. Conduction

Pick out the wrong statement. (A) Fluid movement under the influence of buoyant forces resulting from change in density takes place in case of natural convection (B) The ratio NNu /NRe . Npr is called the Stanton number (C) The Peclet number is a measure of the ratio of energy transport by convection to that by conduction (D) The Colburn jH factor for heat transfer is given by Nst Npr

Description : Pick out the wrong statement. (A) Fluid movement under the influence of buoyant forces resulting from change in density takes place in case of natural convection (B) The ratio NNu /NRe . Npr is ... convection to that by conduction (D) The Colburn jH factor for heat transfer is given by Nst Npr

Last Answer : (D) The Colburn jH factor for heat transfer is given by Nst Npr

Heat flux increases with temperature drop beyond the Leiden frost point in the plot of heat flux vs. temperature drop for a boiling liquid, because (A) Convection becomes important (B) Conduction becomes important (C) Radiation becomes important (D) Sub-cooled boiling occurs

Description : Heat flux increases with temperature drop beyond the Leiden frost point in the plot of heat flux vs. temperature drop for a boiling liquid, because (A) Convection becomes important (B) Conduction becomes important (C) Radiation becomes important (D) Sub-cooled boiling occurs

Last Answer : (C) Radiation becomes important

In pipe flow, heat is transferred from hot wall to the liquid by(A) Conduction only (B) Forced convection only (C) Forced convection and conduction (D) Free and forced convection

Description : In pipe flow, heat is transferred from hot wall to the liquid by(A) Conduction only (B) Forced convection only (C) Forced convection and conduction (D) Free and forced convection

Last Answer : (C) Forced convection and conduction

What refers to the transfer of energy between a solid surface and the adjacent fluid that is in motion?  A. Conduction  B. Convection  C. Radiation  D. Electrification

Description : What refers to the transfer of energy between a solid surface and the adjacent fluid that is in motion?  A. Conduction  B. Convection  C. Radiation  D. Electrification

Last Answer : Convection

____ is the transfer of energy in the form of electromagnetic waves. a. Compulsion c. Convection b. Radiation d. Conduction

Description : ____ is the transfer of energy in the form of electromagnetic waves. a. Compulsion c. Convection b. Radiation d. Conduction

Last Answer : b. Radiation

Loss of heat from untagged steam pipe to the ambient air is by (A) Conduction (B) Convection (C) Radiation (D) All (A), (B) & (C)

Description : Loss of heat from untagged steam pipe to the ambient air is by (A) Conduction (B) Convection (C) Radiation (D) All (A), (B) & (C)

Last Answer : (D) All (A), (B) & (C)

In salt bath furnace, heat is transferred to the charge mainly by (A) Conduction (B) Convection (C) Radiation (D) None of these

Description : In salt bath furnace, heat is transferred to the charge mainly by (A) Conduction (B) Convection (C) Radiation (D) None of these

Last Answer : (A) Conduction

Nusselt number (for forced convection heat transfer) is a function of the __________ number. (A) Prandtl (B) Reynolds (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Nusselt number (for forced convection heat transfer) is a function of the __________ number. (A) Prandtl (B) Reynolds (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Pick out the wrong statement. (A) In drying a solid containing moisture above the critical moisture content the number of degrees of freedom is 2 (B) Sherwood number in mass transfer corresponds to Nusselt number in heat transfer and Schmidt number to Prandtl number (C) Forced convection is relatively more effective in increasing the rate of mass transfer, if Schmidt number is larger (D) 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

Description : Pick out the wrong statement. (A) In drying a solid containing moisture above the critical moisture content the number of degrees of freedom is 2 (B) Sherwood number in mass transfer corresponds to ... tube heat exchangers. At higher pressure, however, it is customary to put gas in the tube side

Last Answer : (C) Forced convection is relatively more effective in increasing the rate of mass transfer, if Schmidt number is larger

Heat transfer co-efficient equation for forced convection, Nu = 0.023 Re 0.8 . Pr n , is not valid, if the value of (A) n = 0.4 is used for heating (B) n = 0.3 is used for cooling (C) Reynolds number for the flow involved is > 10000 (D) Reynolds number for the flow involved is < 2100

Description : Heat transfer co-efficient equation for forced convection, Nu = 0.023 Re 0.8 . Pr n , is not valid, if the value of (A) n = 0.4 is used for heating (B) n = 0.3 is used for cooling (C) Reynolds number for the flow involved is > 10000 (D) Reynolds number for the flow involved is < 2100

Last Answer : (D) Reynolds number for the flow involved is < 2100

By which of the following methods could a cup of hot coffee lose heat if placed on a metal table in a room? (a) Conduction and radiation (b) Conduction and convection (c) Convection and radiation (d) Conduction, convection, radiation and evaporation

Description : By which of the following methods could a cup of hot coffee lose heat if placed on a metal table in a room? (a) Conduction and radiation (b) Conduction and convection (c) Convection and radiation (d) Conduction, convection, radiation and evaporation

Last Answer : Ans:(d)

By what process is heat transmitted from the filament of an evacuated electric bulb to the glass? (a) Conduction (b) Convection (c) Radiation (d) Heat cannot be transmitted through vacuum

Description : By what process is heat transmitted from the filament of an evacuated electric bulb to the glass? (a) Conduction (b) Convection (c) Radiation (d) Heat cannot be transmitted through vacuum

Last Answer : Ans:(c)

Even after sunset, the air near the Earth's surface continue to receive heat due to – (1) Insolation (2) Terrestrial Radiation (3) Conduction (4) Convection

Description : Even after sunset, the air near the Earth's surface continue to receive heat due to – (1) Insolation (2) Terrestrial Radiation (3) Conduction (4) Convection

Last Answer : (2) Terrestrial Radiation Explanation: Even after the sunset when the sun goes down, the incoming radiation from the sun stops, but there is still a lot of radiation that has been absorbed ... i.e. terrestrial radiation heats up the atmosphere more than the incoming solar radiation i.e. insolation

Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in – (1) Conduction (2) Convection (3) Radiation (4) Both conduction and convection

Description : Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in – (1) Conduction (2) Convection (3) Radiation (4) Both conduction and convection

Last Answer : (2) Convection Explanation: The process of heat transfer from one place to an-other place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the ... heated particles of the substance. The fluids (liquids and gases) are heated by this process.

Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in - (1) Conduction (2) Convection (3) Radiation (4) Both conduction and convection

Description : Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in - (1) Conduction (2) Convection (3) Radiation (4) Both conduction and convection

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

Heat from the sun reaches earth by the process of – (1) Conduction (2) Convection (3) Radiation (4) All of the above

Description : Heat from the sun reaches earth by the process of – (1) Conduction (2) Convection (3) Radiation (4) All of the above

Last Answer : (3) Radiation Explanation: In physics, radiation is a process in which energetic particles or energetic waves travel through vacuum, or through mattercontaining media that are not required for their propagation.

Suns heat reaches us by – (1) Conduction (2) Convection (3) Radiation (4) Reflection

Description : Suns heat reaches us by – (1) Conduction (2) Convection (3) Radiation (4) Reflection

Last Answer : (3) Radiation Explanation: Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. The sun' ... frequencies), but those from the sun are mainly infra-red, visible, and ultra-violet.

Heat from the Sun reaches the Earth by (1) Reflection (2) Conduction (3) Radiation (4) Convection

Description : Heat from the Sun reaches the Earth by (1) Reflection (2) Conduction (3) Radiation (4) Convection

Last Answer : (3) Radiation Explanation: The radiation (light, heat, etc.) travels through the intervening 150,000,000 kilometers in 8 minutes. Radiation is a process in which energetic particles or energetic waves ... waves or sound waves, are usually not considered to be forms of "radiation" in this sense.

A process by which heat is transferred through a material without a bulk movement of the material.  a. Convection  b. Conduction  c. Radiation  d. Emission

Description : A process by which heat is transferred through a material without a bulk movement of the material.  a. Convection  b. Conduction  c. Radiation  d. Emission

Last Answer : Conduction

A process in which heat energy is transferred by the flow of fluid.  a. Convection  b. Conduction  c. Radiation  d. Sublimation

Description : A process in which heat energy is transferred by the flow of fluid.  a. Convection  b. Conduction  c. Radiation  d. Sublimation

Last Answer : Convection

How is heat transferred?  A. By conduction  B. By convection  C. By radiation  D. All of the above

Description : How is heat transferred?  A. By conduction  B. By convection  C. By radiation  D. All of the above

Last Answer : All of the above

____ heating means that the circulation of currents in one region inside a can distributes the heat to another. a. Conduction c. Convection b. Radiation d. Slow

Description : ____ heating means that the circulation of currents in one region inside a can distributes the heat to another. a. Conduction c. Convection b. Radiation d. Slow

Last Answer : c. Convection

The mcrease in heat dissipation by air blasts is due to increase in (a) conduction (b) convection (e) radiation (d) any ofthe above

Description : The mcrease in heat dissipation by air blasts is due to increase in (a) conduction (b) convection (e) radiation (d) any ofthe above

Last Answer : (b) convection

The heat dissipated by from a surface depends upon its temperature and its characteristics like colour, roughness etc. (a) conduction (b) convection (c) radiation (d) any ofthe above

Description : The heat dissipated by from a surface depends upon its temperature and its characteristics like colour, roughness etc. (a) conduction (b) convection (c) radiation (d) any ofthe above

Last Answer : (c) radiation

The heated parts of an electrical machine dissipate heat into their surroundings by which of the following modes of heat dissipation ? (a) Conduction (b) Convection (c) Radiation (d) All ofthe above

Description : The heated parts of an electrical machine dissipate heat into their surroundings by which of the following modes of heat dissipation ? (a) Conduction (b) Convection (c) Radiation (d) All ofthe above

Last Answer : (d) All ofthe above

In EXTRA-TERRESTRIAL SPACE, heat is transferred by: w) conduction x) convection y) conduction and convention z) radiation

Description : In EXTRA-TERRESTRIAL SPACE, heat is transferred by: w) conduction x) convection y) conduction and convention z) radiation

Last Answer : ANSWER: Z -- RADIATION

Heat from the sun reaches the Earth by: w) conduction x) convection y) radiation z) none of the above

Description : Heat from the sun reaches the Earth by: w) conduction x) convection y) radiation z) none of the above

Last Answer : ANSWER: Y -- RADIATION

Heat is transferred from the sun to the earth primarily by: w) conduction x) convection y) radiation z) condensation

Description : Heat is transferred from the sun to the earth primarily by: w) conduction x) convection y) radiation z) condensation 

Last Answer : ANSWER: Y -- RADIATION