The relation, Sc = Pr = 1, is valid, when the mechanism of __________ transfer is same. (A) Heat and mass (B) Mass and momentum (C) Heat and momentum (D) Heat, momentum and mass

The relation, Sc = Pr = 1, is valid, when the mechanism of __________

transfer is same.

(A) Heat and mass

(B) Mass and momentum

(C) Heat and momentum

(D) Heat, momentum and mass

by

1 Answer

Answer :

(A) Heat and mass

by

Related questions

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 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 value of Lewis number (Le = Sc/Pr) for air-water vapour system is around (A) 1 (B) 0.24

Description : The value of Lewis number (Le = Sc/Pr) for air-water vapour system is around (A) 1 (B) 0.24

Last Answer : (A) 1

Lewis number (Le) isA) Sc × Pr (B) Pr × St (C) Sh × Pr (D) St × Sh

Description : Lewis number (Le) isA) Sc × Pr (B) Pr × St (C) Sh × Pr (D) St × Sh

Last Answer : (A) Sc × Pr

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

Lewis number, which is important in problems involving simultaneous heat and mass transfer, is the ratio of (A) Mass diffusivity to momentum diffusivity (B) Thermal diffusivity to mass diffusivity (C) Momentum diffusivity to thermal diffusivity (D) None of these

Description : Lewis number, which is important in problems involving simultaneous heat and mass transfer, is the ratio of (A) Mass diffusivity to momentum diffusivity (B) Thermal diffusivity to mass diffusivity (C) Momentum diffusivity to thermal diffusivity (D) None of these

Last Answer : (B) Thermal diffusivity to mass diffusivity

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 (A) Low Reynold's number (B) Very low Grashoff number (C) Molten metals (D) All (A), (B) and (C)

Description : 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 (A) Low Reynold's number (B) Very low Grashoff number (C) Molten metals (D) All (A), (B) and (C)

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

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

The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are (A) Re.Gz (B) Nu, Pr (C) Nu, Pr, Re (D) Nu, Gz

Description : The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are (A) Re.Gz (B) Nu, Pr (C) Nu, Pr, Re (D) Nu, Gz

Last Answer : (D) Nu, Gz

Overall rate of reaction in a heterogeneous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually __________ the concentration of catalyst, if it doesnot entail a chain mechanism.(A) Proportional to(B) Independent of(C) Inversely proportional to(D) Proportional to the square o

Description : Overall rate of reaction in a heterogeneous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually __________ the concentration of ... to (B) Independent of (C) Inversely proportional to (D) Proportional to the square o

Last Answer : (A) Proportional to

If AB = PQ, BC = QR and AC = PR, then write the congruence relation between the triangles. [Fig. 7.6] -Maths 9th

Description : If AB = PQ, BC = QR and AC = PR, then write the congruence relation between the triangles. [Fig. 7.6] -Maths 9th

Last Answer : Solution :- △ ABC ≅ △PQR

. (NSh /NRe .NSc ) is termed in mass transfer operation as the (A) Stanton number (B) Peclet number (C) Thermal diffusivity (D) Momentum diffusivity

Description : . (NSh /NRe .NSc ) is termed in mass transfer operation as the (A) Stanton number (B) Peclet number (C) Thermal diffusivity (D) Momentum diffusivity

Last Answer : (A) Stanton number

The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = __________ (A) 1 (B) 0.5 (C) 10 (D) 0

Description : The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = __________ (A) 1 (B) 0.5 (C) 10 (D) 0

Last Answer : (A) 1

Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by h = 0.023 (K/D) (DVρ/µ) 0.8 (CP .µ/k) 0.4 . This is valid for the value of NRe equal to (A) < 2100 (B) 2100-4000 (C) > 4000 (D) > 10000

Description : Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by h = 0.023 (K/D) (DVρ/µ) 0.8 (CP .µ/k) 0.4 . This is valid for the value of NRe equal to (A) < 2100 (B) 2100-4000 (C) > 4000 (D) > 10000

Last Answer : (D) > 10000

Dittus-Boelter equation used for the determination of heat transfer co￾efficient is valid (A) For fluids in laminar flow (B) For fluids in turbulent flow (C) When Grashoff number is very important (D) For liquid metals

Description : Dittus-Boelter equation used for the determination of heat transfer co￾efficient is valid (A) For fluids in laminar flow (B) For fluids in turbulent flow (C) When Grashoff number is very important (D) For liquid metals

Last Answer : (B) For fluids in turbulent flow

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)

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

Pick out the wrong statement. (A) The Reynolds analogy for mass transfer is given by Lewis relation and is applicable, when Schmidt number is one (B) Sherwood number for flow in pipes can be expressed as the ratio of the concentration gradient at wall to the overall concentration difference (C) According to film theory for equimolar counter diffusion, the mass transfer coefficient is given by DAB(B)P - 3, Q - 2 (D) The z-component of the total mass flux of a component A in binary mixture of A and B is given by - Dab'.dCA/dz

Description : Pick out the wrong statement. (A) The Reynolds analogy for mass transfer is given by Lewis relation and is applicable, when Schmidt number is one (B) Sherwood number for flow in pipes can be expressed ... flux of a component A in binary mixture of A and B is given by - Dab'.dCA/dz

Last Answer : (C) According to film theory for equimolar counter diffusion, the mass transfer coefficient is given by DAB(B)P - 3, Q - 2

The relation among various mass transfer co-efficients (M.T.C) for ideal gases is given by (where, Kc & Km are M.T.C. for equimolar counter diffusion with concentration & mole fraction respectively as the driving force. and, Kp= M.T.C. for diffusion of a gas through a stagnant inert gas with pressure as driving force.) (A) Kc = Kp = Km (B) Kc = Kp /RT = Km . RT/P (C) Kc = Kp . RT = Km . RT/p (D) None of these

Description : The relation among various mass transfer co-efficients (M.T.C) for ideal gases is given by (where, Kc & Km are M.T.C. for equimolar counter diffusion with concentration & mole fraction respectively as the driving ... (C) Kc = Kp . RT = Km . RT/p (D) None of these

Last Answer : (C) Kc = Kp . RT = Km . RT/p

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

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

__________ number indicates the ratio of the rates of the heat and mass transfer incase of a cooling tower. (A) Sherwood (B) Stanton (C) Lewis (D) Peclet

Description : __________ number indicates the ratio of the rates of the heat and mass transfer incase of a cooling tower. (A) Sherwood (B) Stanton (C) Lewis (D) Peclet

Last Answer : (C) Lewis

Drying of a solid involves __________ transfer. (A) Only heat (B) Only mass (C) Both heat and mass (D) None of these

Description : Drying of a solid involves __________ transfer. (A) Only heat (B) Only mass (C) Both heat and mass (D) None of these

Last Answer : (C) Both heat and mass

In case of cooling towers, the ratio of the rates of heat and mass transfer is indicated by the __________ number. (A) Lewis (B) Grashoff (C) Sherwood

Description : In case of cooling towers, the ratio of the rates of heat and mass transfer is indicated by the __________ number. (A) Lewis (B) Grashoff (C) Sherwood

Last Answer : (A) Lewis

In case of a close thermodynamic system, there is __________ across the boundaries. (A) No heat and mass transfer (B) No mass transfer but heat transfer (C) Mass and energy transfer (D) None of these

Description : In case of a close thermodynamic system, there is __________ across the boundaries. (A) No heat and mass transfer (B) No mass transfer but heat transfer (C) Mass and energy transfer (D) None of these

Last Answer : (B) No mass transfer but heat transfer

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

Energy can neither created nor destroyed. It can only change forms.  a. Conservation of Mass Principle  b. Conservation of Energy Principle  c. Conservation of Momentum Principle  d. Conservation of Heat Principle

Description : Energy can neither created nor destroyed. It can only change forms.  a. Conservation of Mass Principle  b. Conservation of Energy Principle  c. Conservation of Momentum Principle  d. Conservation of Heat Principle

Last Answer : Conservation of Energy Principle

The first law of thermodynamics is the law of  (a) conservation of mass  (b) conservation of energy  (c) conservation of momentum  (d) conservation of heat  (e) conservation of temperature.

Description : The first law of thermodynamics is the law of  (a) conservation of mass  (b) conservation of energy  (c) conservation of momentum  (d) conservation of heat  (e) conservation of temperature.

Last Answer : Answer : b

Which of the following has the same dimension as mass diffusivity? (A) Momentum flux (B) Kinematic viscosity (C) Thermal diffusivity (D) Both (B) and (C)

Description : Which of the following has the same dimension as mass diffusivity? (A) Momentum flux (B) Kinematic viscosity (C) Thermal diffusivity (D) Both (B) and (C)

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

Pick out the wrong statement. (A) The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are the same for NSc = NPr= 1 (B) 1 Nm3 of dry air is lighter than 1Nm3 of humid air (C) The Lewis number of a mixture is unity, when the thermal diffusivity is equal to the mass diffusivity

Description : Pick out the wrong statement. (A) The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are the same for NSc = NPr= 1 (B) 1 Nm3 of dry air is lighter ... ) The Lewis number of a mixture is unity, when the thermal diffusivity is equal to the mass diffusivity

Last Answer : (B) 1 Nm3 of dry air is lighter than 1Nm3 of humid air

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

Analogy between mass and heat transfer is not applicable in case of (A) Same velocity profile or equal eddy diffusivities (B) Thermal or pressure mass diffusion (C) Viscous heating or chemical reaction (D) Both (B) and (C)

Description : Analogy between mass and heat transfer is not applicable in case of (A) Same velocity profile or equal eddy diffusivities (B) Thermal or pressure mass diffusion (C) Viscous heating or chemical reaction (D) Both (B) and (C)

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

For the same heat load and mass flow rate in the tube side of a shell and tube heat exchanger, one may use multipass on the tube side, because it (A) Decreases the pressure drop (B) Decreases the outlet temperature of cooling medium (C) Increases the overall heat transfer coefficient (D) None of these

Description : For the same heat load and mass flow rate in the tube side of a shell and tube heat exchanger, one may use multipass on the tube side, because it (A) Decreases the pressure drop (B) ... the outlet temperature of cooling medium (C) Increases the overall heat transfer coefficient (D) None of these

Last Answer : (C) Increases the overall heat transfer coefficient

Under which of the following conditions is the relation, `Delta H = Delta E + P Delta V` valid for a system :-

Description : Under which of the following conditions is the relation, `Delta H = Delta E + P Delta V` valid for a system :-

Last Answer : Under which of the following conditions is the relation, `Delta H = Delta E + P ... and pressure D. Constant temperature, pressure and composition

Logical reasoning is based on: (A) Truth of involved propositions (B) Valid relation among the involved propositions (C) Employment of symbolic language (D) Employment of ordinary language

Description : Logical reasoning is based on: (A) Truth of involved propositions (B) Valid relation among the involved propositions (C) Employment of symbolic language (D) Employment of ordinary language

Last Answer : (B) Valid relation among the involved propositions

Pick out the wrong statement. (A) Momentum transfer in laminar flow results from velocity gradient (B) A fluid in equilibrium is not free from shear stress (C) The viscosity of a non-Newtonian fluid is a function of temperature only (D) Both (B) and (C)

Description : Pick out the wrong statement. (A) Momentum transfer in laminar flow results from velocity gradient (B) A fluid in equilibrium is not free from shear stress (C) The viscosity of a non-Newtonian fluid is a function of temperature only (D) Both (B) and (C)

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

Momentum transfer in laminar flow of fluids results due to the (A) Viscosity (B) Density (C) Velocity gradient (D) None of these

Description : Momentum transfer in laminar flow of fluids results due to the (A) Viscosity (B) Density (C) Velocity gradient (D) None of these

Last Answer : (C) Velocity gradient

In turbulent flow, the (A) Fluid particles move in an orderly manner (B) Momentum transfer is on molecular scale only (C) Shear stress is caused more effectively by cohesion than momentum transfer (D) Shear stresses are generally larger than in a similar laminar flow

Description : In turbulent flow, the (A) Fluid particles move in an orderly manner (B) Momentum transfer is on molecular scale only (C) Shear stress is caused more effectively by cohesion than momentum transfer (D) Shear stresses are generally larger than in a similar laminar flow

Last Answer : (D) Shear stresses are generally larger than in a similar laminar flow

Fluid resistance to shear depends upon its (A) Rate of transfer of molecular momentum (B) Cohesion (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Fluid resistance to shear depends upon its (A) Rate of transfer of molecular momentum (B) Cohesion (C) Both (A) and (B) (D) Neither (A) nor (B)

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

State the relation between relative velocity and motion of link in mechanism.

Description : State the relation between relative velocity and motion of link in mechanism.

Last Answer : Relation between Relative Velocity and motion of link in mechanism: The relative velocity is the velocity of any point with respect to any other some point on the same link. Let,  V be the relative velocity of one ... of same link in meter Then, the relation is expressed as;  V = r x ω m/sec 

The heat transfer co-efficient in film type condensation is __________ that for dropwise condensation. (A) Greater than (B) Lower than (C) Is same as (D) Half

Description : The heat transfer co-efficient in film type condensation is __________ that for dropwise condensation. (A) Greater than (B) Lower than (C) Is same as (D) Half

Last Answer : (B) Lower than

Two objects A and B are moving with same momentum. Mass of object 'B' is greater then mass of object 'A'. Which of the two object will have higher kinetic energy? -Physics

Description : Two objects A and B are moving with same momentum. Mass of object 'B' is greater then mass of object 'A'. Which of the two object will have higher kinetic energy? -Physics

Last Answer : Let m1​ and m2​ be the masses of the body Let m1​>m2​Given that m1​v1​=m2​v2​v2​v1​​=m1​m2​​∴ Ratio between their kinetic energies , =K2​K1​​=21​m2​v22​21​m1​v12​​⟹K2​K1​​=m2​m1​​×m12​

A metal ball and a rubber ball, both having the same mass, strike a wall normally with the same velocity. The rubber ball rebounds and the metal ball does not rebound. It can be concluded that – (1) The rubber ball suffers greater change in momentum (2) The metal ball suffers greater change in momentum (3) Both suffer the same change in momentum (4) The initial momentum of the rubber ball is greater than that of the metal ball

Description : A metal ball and a rubber ball, both having the same mass, strike a wall normally with the same velocity. The rubber ball rebounds and the metal ball does not rebound. It can be concluded that - ... change in momentum (4) The initial momentum of the rubber ball is greater than that of the metal ball

Last Answer : (1) The rubber ball suffers greater change in momentum

If two different gases have the same volume, temperature, and pressure and behave like ideal gases, they will also be identical in which one of the following ways? w) average molecular velocity x) total mass y) total molecular kinetic energy z) average momentum per molecule

Description : If two different gases have the same volume, temperature, and pressure and behave like ideal gases, they will also be identical in which one of the following ways? w) average molecular velocity x) total mass y) total molecular kinetic energy z) average momentum per molecule

Last Answer : ANSWER: Y -- TOTAL MOLECULAR KINETIC ENERGY

When the velocity of an object is tripled, another quantity which is tripled at the same time is the object's: w) momentum x) potential energy y) kinetic energy z) mass

Description : When the velocity of an object is tripled, another quantity which is tripled at the same time is the object's: w) momentum x) potential energy y) kinetic energy z) mass

Last Answer : ANSWER: W -- MOMENTUM

A metal ball and a rubber ball, both having the same mass, strike a wall normally with the same velocity. The rubber ball rebounds and the metal ball does not rebound. It can be concluded that (1) The rubber ball suffers greater change in momentum (2) The metal ball suffers greater change in momentum (3) Both suffer the same change in momentum (4) The initial momentum of the rubber ball is greater than that of the metal ball

Description : A metal ball and a rubber ball, both having the same mass, strike a wall normally with the same velocity. The rubber ball rebounds and the metal ball does not rebound. It can be concluded that ( ... change in momentum (4) The initial momentum of the rubber ball is greater than that of the metal ball

Last Answer : The rubber ball suffers greater change in momentum 

In physical terms, Schmidt number means (A) Thermal diffusivity/mass diffusivity(B) Thermal diffusivity/momentum diffusivity(C) Momentum diffusivity/mass diffusivity(D) Mass diffusivity/thermal diffusivity

Description : In physical terms, Schmidt number means (A) Thermal diffusivity/mass diffusivity (B) Thermal diffusivity/momentum diffusivity (C) Momentum diffusivity/mass diffusivity (D) Mass diffusivity/thermal diffusivity

Last Answer : (C) Momentum diffusivity/mass diffusivity

The Schmidt number which is defined as, μ/ρ D, is the ratio of the (A) Momentum diffusivity to the mass diffusivity (B) Thermal diffusivity to the mass diffusivity (C) Momentum diffusivity to the thermal diffusivity (D) None of these

Description : The Schmidt number which is defined as, μ/ρ D, is the ratio of the (A) Momentum diffusivity to the mass diffusivity (B) Thermal diffusivity to the mass diffusivity (C) Momentum diffusivity to the thermal diffusivity (D) None of these

Last Answer : (A) Momentum diffusivity to the mass diffusivity

Prandtl number is the ratio of (A) Mass diffusivity to thermal diffusivity (B) Momentum diffusivity to thermal diffusivity (C) Thermal diffusivity to mass diffusivity (D) Thermal diffusivity to momentum diffusivity

Description : Prandtl number is the ratio of (A) Mass diffusivity to thermal diffusivity (B) Momentum diffusivity to thermal diffusivity (C) Thermal diffusivity to mass diffusivity (D) Thermal diffusivity to momentum diffusivity

Last Answer : (B) Momentum diffusivity to thermal diffusivity

Prandtl number is the ratio of (A) Momentum diffusivity to mass diffusivity (B) Momentum diffusivity to thermal diffusivity (C) Thermal diffusivity to mass diffusivity (D) Thermal diffusivity to momentum diffusivity

Description : Prandtl number is the ratio of (A) Momentum diffusivity to mass diffusivity (B) Momentum diffusivity to thermal diffusivity (C) Thermal diffusivity to mass diffusivity (D) Thermal diffusivity to momentum diffusivity

Last Answer : (B) Momentum diffusivity to thermal diffusivity