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)

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)


by

1 Answer

Answer :

(C) Both (A) & (B)


by

Related questions

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

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

Critical value of the __________ number governs the transition from laminar to turbulent flow in free convection heat transfer. (A) Grashoff (B) Reynolds (C) Both 'a' & 'b' (D) Prandtl & Grashoff

Description : Critical value of the __________ number governs the transition from laminar to turbulent flow in free convection heat transfer. (A) Grashoff (B) Reynolds (C) Both 'a' & 'b' (D) Prandtl & Grashoff

Last Answer : (D) Prandtl & Grashoff

jH factor for heat transfer depends upon the __________ number. (A) Biot (B) Nusselt (C) Reynolds (D) Prandtl

Description : jH factor for heat transfer depends upon the __________ number. (A) Biot (B) Nusselt (C) Reynolds (D) Prandtl

Last Answer : (C) Reynolds

Pick out the wrong statement pertaining to the analogy between equations of heat and mass transfer operations. (A) Sherwood number in mass transfer is analogous to Nusselt number in heat transfer (B) Prandtl number in heat transfer is analogous to Schmidt number in mass transfer (C) Reynolds number in mass transfer is analogous to Grashoff number in heat transfer (D) Reynolds number remains the same in both heat and mass transfer

Description : Pick out the wrong statement pertaining to the analogy between equations of heat and mass transfer operations. (A) Sherwood number in mass transfer is analogous to Nusselt number in heat transfer ... heat transfer (D) Reynolds number remains the same in both heat and mass transfer

Last Answer : (C) Reynolds number in mass transfer is analogous to Grashoff number in heat transfer

Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of (A) Grashoff number (B) Grashoff number & Reynolds number (C) Reynolds number (D) Grashoff number & Prandtl number

Description : Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of (A) Grashoff number (B) Grashoff number & Reynolds number (C) Reynolds number (D) Grashoff number & Prandtl number

Last Answer : Option D

jH factor for heat transfer is not a function of the __________ number. (A) Reynolds (B) Nusselt (C) Grashoff (D) Both (B) & (C)

Description : jH factor for heat transfer is not a function of the __________ number. (A) Reynolds (B) Nusselt (C) Grashoff (D) Both (B) & (C)

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

Which of the following is unimportant in forced convection? (A) Reynolds number (B) Prandtl number (C) Grashoff number (D) None of these

Description : Which of the following is unimportant in forced convection? (A) Reynolds number (B) Prandtl number (C) Grashoff number (D) None of these

Last Answer : (C) Grashoff number

Which of the following forced convection heat transfer equation accounts for the liquid viscosity effect for viscous liquids? (A) Dittus-Boelter equation (B) Sieder-Tate equation (C) Nusselt equation (D) None of these

Description : Which of the following forced convection heat transfer equation accounts for the liquid viscosity effect for viscous liquids? (A) Dittus-Boelter equation (B) Sieder-Tate equation (C) Nusselt equation (D) None of these

Last Answer : (B) Sieder-Tate equation

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)

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

The dimensionless group in mass transfer that is equivalent to Prandtl number in heat transfer is (A) Nusselt number (B) Sherwood number (C) Schmidt number (D) Stanton numbe

Description : The dimensionless group in mass transfer that is equivalent to Prandtl number in heat transfer is (A) Nusselt number (B) Sherwood number (C) Schmidt number (D) Stanton numbe

Last Answer : (C) Schmidt number

In forced convection, the Nusselt number is a function of (A) Re and Pr (B) Re and Gr (C) Pr and Gr (D) Re and Sc

Description : In forced convection, the Nusselt number is a function of (A) Re and Pr (B) Re and Gr (C) Pr and Gr (D) Re and Sc

Last Answer : (A) Re and Pr

Natural convection is characterised by (A) Grashoff number (B) Peclet number (C) Reynolds number (D) Prandtl number

Description : Natural convection is characterised by (A) Grashoff number (B) Peclet number (C) Reynolds number (D) Prandtl number

Last Answer : (A) Grashoff number

The Sieder-Tate correlation for heat transfer in turbulent flow in pipe gives Nu α Re 0.8 , where, Nu is the Nusselt number and Re is the Reynolds number for the flow. Assuming that this relation is valid, the heat transfer co-efficient varies with the pipe diameter (D) as (A) D-1.8 (B) D-0.2 (C) D0.2 (D) D1.8

Description : The Sieder-Tate correlation for heat transfer in turbulent flow in pipe gives Nu α Re 0.8 , where, Nu is the Nusselt number and Re is the Reynolds number for the flow. Assuming that this relation is valid, the heat transfer co-efficient ... pipe diameter (D) as (A) D-1.8 (B) D-0.2 (C) D0.2 (D) D1.8

Last Answer : (B) D-0.2

The important dimensional group involved in the power requirement calculation in mixing operation is the __________ number. (A) Reynold's (B) Froude (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The important dimensional group involved in the power requirement calculation in mixing operation is the __________ number. (A) Reynold's (B) Froude (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Fanning friction factor for laminar flow of fluid in a circular pipe is (A) Not a function of the roughness of pipe wall (B) Inversely proportional to Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Fanning friction factor for laminar flow of fluid in a circular pipe is (A) Not a function of the roughness of pipe wall (B) Inversely proportional to Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)

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

The non-dimensional temperature gradient in a liquid at the wall of a pipe is the (A) Heat flux (B) Nusselt number (C) Prandtl number (D) Schmidt number

Description : The non-dimensional temperature gradient in a liquid at the wall of a pipe is the (A) Heat flux (B) Nusselt number (C) Prandtl number (D) Schmidt number

Last Answer : (A) Heat flux

The ratio of momentum diffusivity to thermal diffusivity is the __________ number. (A) Prandtl (B) Nusselt (C) Stanton (D) Grashoff

Description : The ratio of momentum diffusivity to thermal diffusivity is the __________ number. (A) Prandtl (B) Nusselt (C) Stanton (D) Grashoff

Last Answer : (A) Prandtl

The ratio of kinematic viscosity to thermal diffusivity is called the __________ number. (A) Peclet (B) Prandtl (C) Stanton (D) Nusselt

Description : The ratio of kinematic viscosity to thermal diffusivity is called the __________ number. (A) Peclet (B) Prandtl (C) Stanton (D) Nusselt

Last Answer : (B) Prandtl

Cpµ/K is termed as the __________ number. (A) Grashoff (B) Nusselt (C) Prandtl (D) Stanton

Description : Cpµ/K is termed as the __________ number. (A) Grashoff (B) Nusselt (C) Prandtl (D) Stanton

Last Answer : (C) Prandtl

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

Isothermal turbulent flow of a fluid results in decrease of its pressure, which depends on the (A) Wall roughness (B) Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Isothermal turbulent flow of a fluid results in decrease of its pressure, which depends on the (A) Wall roughness (B) Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Nusselt number is related to the Reynolds number (Re) in turbulent & laminar flow respectively as (A) Re0.5, Re0.8 (B) Re0.8, Re-0.5 (C) Re0.8, Re0.5 (D) Re-0.8, Re0.5

Description : Nusselt number is related to the Reynolds number (Re) in turbulent & laminar flow respectively as (A) Re0.5, Re0.8 (B) Re0.8, Re-0.5 (C) Re0.8, Re0.5 (D) Re-0.8, Re0.5

Last Answer : (C) Re0.8, Re0.5

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

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

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

Last Answer : (A) Transient heat conduction

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

The hydrodynamic and thermal boundary layers will merge, when (A) Prandtl number is one (B) Schmidt number tends to infinity (C) Nusselt number tends to infinity (D) Archimedes number is greater than 10000

Description : The hydrodynamic and thermal boundary layers will merge, when (A) Prandtl number is one (B) Schmidt number tends to infinity (C) Nusselt number tends to infinity (D) Archimedes number is greater than 10000

Last Answer : (A) Prandtl number is one

Nusselt number is related to Grashoff number (Gr) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as (A) Gr0.25, Gr (B) Gr0.25, Gr0.33 (C) Gr, Gr0.25 (D) Gr0.33, Gr0.25

Description : Nusselt number is related to Grashoff number (Gr) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as (A) Gr0.25, Gr (B) Gr0.25, Gr0.33 (C) Gr, Gr0.25 (D) Gr0.33, Gr0.25

Last Answer : Option A

Pick out the wrong statement. (A) In case of heat transfer by purely forced convection, GR /Re 2 ≤ 1 (B) The equivalent diameter of heat transfer for a duct of square cross￾section (having each side as 'x') is equal to 4x (C) Distillation process is not the same as evaporation (D) The effectiveness of nucleate boiling depends basically on the ease with which the bubbles are formed and detached from the heating surface

Description : Pick out the wrong statement. (A) In case of heat transfer by purely forced convection, GR /Re 2 ≤ 1 (B) The equivalent diameter of heat transfer for a duct of ... nucleate boiling depends basically on the ease with which the bubbles are formed and detached from the heating surface

Last Answer : (B) The equivalent diameter of heat transfer for a duct of square cross￾section (having each side as 'x') is equal to 4x

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

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

In forced convection, the heat transfer depends on(A) Re, Pr (B) Re, Gr (C) Mainly Gr (D) Re only

Description : In forced convection, the heat transfer depends on (A) Re, Pr (B) Re, Gr (C) Mainly Gr (D) Re only

Last Answer : (A) Re, Pr

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

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

Forced recirculation of furnace gases is practised (A) To increase heat transfer by convection (B) To ensure uniform temperature (C) In furnaces, operating below 750°C (D) All (A), (B) and (C)

Description : Forced recirculation of furnace gases is practised (A) To increase heat transfer by convection (B) To ensure uniform temperature (C) In furnaces, operating below 750°C (D) All (A), (B) and (C)

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

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

The equation, Nst = (f/2)/[1 + 5 (Npr - 1) √(f/2)], corresponds to __________ analogy. (A) Von-Karman (B) Reynolds (C) Colburn (D) Prandtl

Description : The equation, Nst = (f/2)/[1 + 5 (Npr - 1) √(f/2)], corresponds to __________ analogy. (A) Von-Karman (B) Reynolds (C) Colburn (D) Prandtl

Last Answer : (D) Prandtl

The equation, (NSt × N2/3 Pr ) = f/2, is the __________ analogy. (A) Colburn (B) Reynolds (C) Prandtl (D) None of these

Description : The equation, (NSt × N2/3 Pr ) = f/2, is the __________ analogy. (A) Colburn (B) Reynolds (C) Prandtl (D) None of these

Last Answer : (A) Colburn

The equation, Nst = f/2, is the __________ analogy. (A) Colburn (B) Reynolds (C) Prandtl (D) None o

Description : The equation, Nst = f/2, is the __________ analogy. (A) Colburn (B) Reynolds (C) Prandtl (D) None o

Last Answer : (B) Reynolds

Corresponding to Nusselt number in heat transfer, the dimensionless group in mass transfer is the __________ number. (A) Sherwood (B) Schmidt (C) Peclet (D) Stanton

Description : Corresponding to Nusselt number in heat transfer, the dimensionless group in mass transfer is the __________ number. (A) Sherwood (B) Schmidt (C) Peclet (D) Stanton

Last Answer : (A) Sherwood

Give expression for the following and explain the terms involved. (i) Nusselt number (ii) Prandtl number

Description : Give expression for the following and explain the terms involved. (i) Nusselt number (ii) Prandtl number

Last Answer : 1. Nusselt NumberNNU= hd/k  h – fim heat transfer coefficient  d - diameter of pipe  k – thermal conductivity of fluid 2. Prandtl Number NPR -Cp µ/k Cp– specific heat of fluid µ - viscosity of fluid  k – thermal conductivity

In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Forced circulation evaporators are normally used for concentrating liquids having (A) Scaling characteristics (B) High viscosity (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Forced circulation evaporators are normally used for concentrating liquids having (A) Scaling characteristics (B) High viscosity (C) Both (A) & (B) (D) Neither (A) nor (B)

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

In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

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

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

Corresponding to Prandtl number in heat transfer, the dimensionless group in mass transfer is the __________ number. (A) Schmidt (B) Sherwood (C) Peclet (D) Stanton

Description : Corresponding to Prandtl number in heat transfer, the dimensionless group in mass transfer is the __________ number. (A) Schmidt (B) Sherwood (C) Peclet (D) Stanton

Last Answer : (A) Schmidt

Which of the following is concerned with both heat and mass transfer? (A) Lewis relationship (B) Nusselt number (C) Kutateladze number (D) Froude number

Description : Which of the following is concerned with both heat and mass transfer? (A) Lewis relationship (B) Nusselt number (C) Kutateladze number (D) Froude number

Last Answer : (A) Lewis relationship

Prandtl and Reynold's analogies are identical for Prandtl number value of (A) 0 (B) 0.5 (C) 1 (D) 5

Description : Prandtl and Reynold's analogies are identical for Prandtl number value of (A) 0 (B) 0.5 (C) 1 (D) 5

Last Answer : (C) 1

Prandtl and Reynolds analogy are same, when Prandtl number is (A) 0.5 (B) 1 (C) > 2 (D) 1.5

Description : Prandtl and Reynolds analogy are same, when Prandtl number is (A) 0.5 (B) 1 (C) > 2 (D) 1.5

Last Answer : (B) 1