In a heat exchanger, the rate of heat transfer from the hot fluid to the cold fluid (A) Varies directly as the area and the LMTD (B) Directly proportional to LMTD and inversely proportional to the area (C) Varies as square of the area (D) None of these

In a heat exchanger, the rate of heat transfer from the hot fluid to the
cold fluid
(A) Varies directly as the area and the LMTD
(B) Directly proportional to LMTD and inversely proportional to the area
(C) Varies as square of the area
(D) None of these
by

1 Answer

Answer :

(A) Varies directly as the area and the LMTD
by

Related questions

In a 1-1 concurrent heat exchanger, if the tube side fluid outlet temperature is equal to the shell side fluid outlet temperature, then the LMTD is (A) ∞ (B) 0 (C) Equal to the difference between hot and cold fluids inlet temperature (D) Equal to the difference between hot fluid inlet temperature and cold fluid outlet temperature

Description : In a 1-1 concurrent heat exchanger, if the tube side fluid outlet temperature is equal to the shell side fluid outlet temperature, then the LMTD is (A) ∞ (B) 0 ... temperature (D) Equal to the difference between hot fluid inlet temperature and cold fluid outlet temperature

Last Answer : (B) 0

Pick out the wrong statement. (A) The controlling resistance in case of heating of air by condensing steam is in the air film (B) The log mean temperature difference (LMTD) for counter flow and parallel flow can be theoretically same when any one of the fluids (hot or cold fluid) passes through the heat exchanger at constant temperature (C) In case of a 1 - 2 shell and tube heat exchanger, the LMTD correction factor value increases sharply, when a temperature cross occurs (D) Phase change in case of a pure fluid at a given pressure from liquid to vapor or vice-versa occurs at saturation temperature

Description : Pick out the wrong statement. (A) The controlling resistance in case of heating of air by condensing steam is in the air film (B) The log mean temperature difference (LMTD) for ... a pure fluid at a given pressure from liquid to vapor or vice-versa occurs at saturation temperature

Last Answer : (C) In case of a 1 - 2 shell and tube heat exchanger, the LMTD correction factor value increases sharply, when a temperature cross occurs

LMTD for counter-flow and parallel flow heat exchanger will be the same, when the (A) Cold fluid is heated to a certain temperature by condensing steam (isothermal fluid) (B) Outlet temperature of both the hot and cold fluid are same (C) Outlet temperature of hot fluid is less than the outlet temperature of the cold fluid (D) None of these

Description : LMTD for counter-flow and parallel flow heat exchanger will be the same, when the (A) Cold fluid is heated to a certain temperature by condensing steam (isothermal fluid) (B) Outlet temperature of ... temperature of hot fluid is less than the outlet temperature of the cold fluid (D) None of these

Last Answer : (A) Cold fluid is heated to a certain temperature by condensing steam (isothermal fluid)

In a parallel flow heat exchanger, if the outlet temperature of hot and cold fluids are the same, then the log mean temperature difference (LMTD) is (A) Minimum (B) Maximum (C) Zero (D) Infinity

Description : In a parallel flow heat exchanger, if the outlet temperature of hot and cold fluids are the same, then the log mean temperature difference (LMTD) is (A) Minimum (B) Maximum (C) Zero (D) Infinity

Last Answer : (C) Zero

In case of a multipass shell and tube heat exchanger, the temperature drop in the fluid (A) Is inversely proportional to the resistance across which the drop occurs (B) And the wall are proportional to individual resistances (C) And the wall is not related (D) None of these

Description : In case of a multipass shell and tube heat exchanger, the temperature drop in the fluid (A) Is inversely proportional to the resistance across which the drop occurs (B) And the wall are proportional to individual resistances (C) And the wall is not related (D) None of these

Last Answer : (B) And the wall are proportional to individual resistances

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

A fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter 'd'. For a fixed mass flow rate, the tube side heat transfer co￾efficient for turbulent flow conditions is proportional to (A) d 0.8 (B) d -0.2 (C) d -1 (D) d -1.8

Description : A fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter 'd'. For a fixed mass flow rate, the tube side heat transfer co￾efficient for turbulent flow conditions is proportional to (A) d 0.8 (B) d -0.2 (C) d -1 (D) d -1.8

Last Answer : (B) d -0.2

In the Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass is __________ the fluid viscosity. (A) Directly proportional to (B) Inversely proportional to (C) Inversely proportional to the square root of (D) Independent of

Description : In the Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass is __________ the fluid viscosity. (A) Directly proportional to (B) Inversely proportional to (C) Inversely proportional to the square root of (D) Independent of

Last Answer : (B) Inversely proportional to

Log mean temperature difference (LMTD) cannot be used, if (A) Heat transfer co-efficient over the entire heat exchanger is not constant (B) There exists an unsteady state (C) The heat capacity is not constant and there is a phase change (D) None of these

Description : Log mean temperature difference (LMTD) cannot be used, if (A) Heat transfer co-efficient over the entire heat exchanger is not constant (B) There exists an unsteady state (C) The heat capacity is not constant and there is a phase change (D) None of these

Last Answer : (D) None of these

For a heat exchanger, will the overall heat transfer coefficient increase along with an increase in LMTD (log mean temperature difference) around the unit?

Description : For a heat exchanger, will the overall heat transfer coefficient increase along with an increase in LMTD (log mean temperature difference) around the unit?

Last Answer : The overall heat transfer coefficient is generally weakly dependent on temperature. As the temperatures of the fluids change, the degree to which the overall heat transfer coefficient will be affected depends ... with temperature as I've noted and the U-value will decrease over time with fouling).

Nusselt number/Biot number varies (A) Inversely with thermal conductivity (B) Directly with heat transfer co-efficient (C) Directly with thermal conductivity (D) Inversely with the dimension of the solid

Description : Nusselt number/Biot number varies (A) Inversely with thermal conductivity (B) Directly with heat transfer co-efficient (C) Directly with thermal conductivity (D) Inversely with the dimension of the solid

Last Answer : (A) Inversely with thermal conductivity

The terminal velocity of a sphere setting in a viscous fluid varies as : (a) The Reynolds number (b) The square of its diameter (c) Directly proportional to the viscosity of the fluid (d) Its diameter

Description : The terminal velocity of a sphere setting in a viscous fluid varies as : (a) The Reynolds number (b) The square of its diameter (c) Directly proportional to the viscosity of the fluid (d) Its diameter

Last Answer : (b) The square of its diameter

Out of the following four assumptions used in the derivation of theequation for LMTD[LMTD = (∆t1- ∆t2)/ln(∆t1/∆t2)], which one is subject to the largest deviationin practice ?(A) Constant overall heat transfer co-efficient.(B) Constant rate of fluid flow(C) Constant specific heat(D) No partial phase change in the system

Description : Out of the following four assumptions used in the derivation of theequation for LMTD [LMTD = (∆t1 - ∆t2 )/ln(∆t1 /∆t2 )], which one is subject to the largest deviation in practice ? (A) Constant ... (B) Constant rate of fluid flow (C) Constant specific heat (D) No partial phase change in the system

Last Answer : (B) Constant rate of fluid flow

Pick out the wrong statement. (A) Heat transfer by radiation cannot occur across an absolute volume (B) In case of a shell and tube heat exchanger, the pressure drop through the shell is proportional to the number of times the fluid crosses the bundle between baffles (C) Propagation velocity for travel of heat radiation through vacuum is equal to the velocity of the light (D) The amount of heat involved in the condensation or vaporisation of 1 kg of a fluid is the same

Description : Pick out the wrong statement. (A) Heat transfer by radiation cannot occur across an absolute volume (B) In case of a shell and tube heat exchanger, the pressure drop through the shell is ... The amount of heat involved in the condensation or vaporisation of 1 kg of a fluid is the same

Last Answer : (A) Heat transfer by radiation cannot occur across an absolute volume

At very high concentration of enzymes, the rate of fermentation chemical reaction is __________ the concentration of reactants. (A) Independent of (B) Directly proportional to (C) Inversely proportional to (D) Proportional to the square of

Description : At very high concentration of enzymes, the rate of fermentation chemical reaction is __________ the concentration of reactants. (A) Independent of (B) Directly proportional to (C) Inversely proportional to (D) Proportional to the square of

Last Answer : (A) Independent of

In a shell and tube heat exchanger, (A) The temperature drops in the two fluids and the wall are proportional to individual resistances (B) The temperature drop is inversely proportional to the resistance across which the drop occurs (C) There is no relationship between temperature drop and resistance (D) The relationship is not generalised

Description : In a shell and tube heat exchanger, (A) The temperature drops in the two fluids and the wall are proportional to individual resistances (B) The temperature drop is inversely proportional to ... ) There is no relationship between temperature drop and resistance (D) The relationship is not generalised

Last Answer : (A) The temperature drops in the two fluids and the wall are proportional to individual resistances

How does the electric field strength of a standard broadcast station vary with the distance from the antenna? A. The field strength of a standard broadcast station vary with the distance from the antenna B. The field strength is directly proportional to the distance from the antenna C. The field strength remains constant regardless of the distance from the antenna D. The field strength varies inversely as the distance from the antenna

Description : How does the electric field strength of a standard broadcast station vary with the distance from the antenna? A. The field strength of a standard broadcast station vary with the distance from ... the distance from the antenna D. The field strength varies inversely as the distance from the antenna

Last Answer : D. The field strength varies inversely as the distance from the antenna

According to Newton's law of viscosity, the shear stress on a layer of a fluid is __________ to the rate of shear strain. (A) Equal to (B) Directly proportional (C) Inversely proportional (D) None of these

Description : According to Newton's law of viscosity, the shear stress on a layer of a fluid is __________ to the rate of shear strain. (A) Equal to (B) Directly proportional (C) Inversely proportional (D) None of these

Last Answer : Answer: Option B

The head loss in turbulent flow in a pipe varies (A) Directly as the velocity (B) Inversely as the square of the velocity (C) Approximately as the square of the velocity (D) Inversely as the square of the diameter

Description : The head loss in turbulent flow in a pipe varies (A) Directly as the velocity (B) Inversely as the square of the velocity (C) Approximately as the square of the velocity (D) Inversely as the square of the diameter

Last Answer : (C) Approximately as the square of the velocity

. The pressure and power requirement of a gas fan at constant speed & capacity varies __________ the gas density. (A) Directly as (B) Inversely as square root of (C) Inversely as (D) As square of

Description : . The pressure and power requirement of a gas fan at constant speed & capacity varies __________ the gas density. (A) Directly as (B) Inversely as square root of (C) Inversely as (D) As square of

Last Answer : (A) Directly as

A fluid is termed as the Newtonian fluid, when the shear stress is __________ the velocity gradient. (A) Independent of (B) Inversely proportional to (C) Directly proportional to (D) None of these

Description : A fluid is termed as the Newtonian fluid, when the shear stress is __________ the velocity gradient. (A) Independent of (B) Inversely proportional to (C) Directly proportional to (D) None of these

Last Answer : (C) Directly proportional to

In case of parallel flow heat exchanger, the lowest temperature theoretically attainable by the hot fluid is __________ the outlet temperature of the cold fluid. (A) Equal to (B) More than (C) Less than (D) Either more or less than (depending upon the fluid)

Description : In case of parallel flow heat exchanger, the lowest temperature theoretically attainable by the hot fluid is __________ the outlet temperature of the cold fluid. (A) Equal to (B) More than (C) Less than (D) Either more or less than (depending upon the fluid)

Last Answer : (A) Equal to

In a counter flow heat exchanger, hot fluid enters at 170°C & leaves at 150°C, while the cold fluid enters at 50°C & leaves at 70°C. The arithmetic mean temperature difference in this case is __________ °C. (A) 20 (B) 60 (C) 120 (D) ∞

Description : In a counter flow heat exchanger, hot fluid enters at 170°C & leaves at 150°C, while the cold fluid enters at 50°C & leaves at 70°C. The arithmetic mean temperature difference in this case is __________ °C. (A) 20 (B) 60 (C) 120 (D) ∞

Last Answer : (D) ∞

In counter flow compared to parallel flow, (A) LMTD is greater (B) Less surface area is required for a given heat transfer rate (C) Both (A) and (B) (D) More surface area is required for a given heat transfer rate

Description : In counter flow compared to parallel flow, (A) LMTD is greater (B) Less surface area is required for a given heat transfer rate (C) Both (A) and (B) (D) More surface area is required for a given heat transfer rate

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

The outlet temperature of cooling water in a heat exchanger is generally not allowed to exceed above 50°C in industrial practice mainly to avoid (A) Its evaporation loss (B) Excessive corrosion (C) Uneconomic LMTD (D) Decrease in heat exchanger efficiency

Description : The outlet temperature of cooling water in a heat exchanger is generally not allowed to exceed above 50°C in industrial practice mainly to avoid (A) Its evaporation loss (B) Excessive corrosion (C) Uneconomic LMTD (D) Decrease in heat exchanger efficiency

Last Answer : (B) Excessive corrosion

LMTD correction factor which is to be applied for a cross-flow heat exchanger increases with increase in the number of shell passes. Its value for a single pass cross flow heat exchanger is (A) 0 (B) 1 (C) > 1 (D) < 1

Description : LMTD correction factor which is to be applied for a cross-flow heat exchanger increases with increase in the number of shell passes. Its value for a single pass cross flow heat exchanger is (A) 0 (B) 1 (C) > 1 (D) < 1

Last Answer : (D) < 1

In a liquid-liquid heat exchanger, for the same process temperature, the ratio of the LMTD in parallel flow to the LMTD in counter flow is always (A) < 1 (B) > 1 (C) 1 (D) ∞

Description : In a liquid-liquid heat exchanger, for the same process temperature, the ratio of the LMTD in parallel flow to the LMTD in counter flow is always (A) < 1 (B) > 1 (C) 1 (D) ∞

Last Answer : (A) < 1

It is not recommended to use a 1-2 shell and tube heat exchanger for a particular heat duty, whenever the LMTD correction factor is (A) > 0.75 (B) < 0.75 (C) < 0.50 (D) < 0.25

Description : It is not recommended to use a 1-2 shell and tube heat exchanger for a particular heat duty, whenever the LMTD correction factor is (A) > 0.75 (B) < 0.75 (C) < 0.50 (D) < 0.25

Last Answer : (B) < 0.75

LMTD can't be used as such without a correction factor for the (A) Multipass heat exchanger (B) Baffled heat exchanger (C) Condensation of mixed vapour in a condenser (D) All (A) (B) and (C)

Description : LMTD can't be used as such without a correction factor for the (A) Multipass heat exchanger (B) Baffled heat exchanger (C) Condensation of mixed vapour in a condenser (D) All (A) (B) and (C)

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

For a multipass shell and tube heat exchanger, the LMTD correction factor is always (A) 1 (B) > 1 (C) < 1 (D) Between 1 & 2

Description : For a multipass shell and tube heat exchanger, the LMTD correction factor is always (A) 1 (B) > 1 (C) < 1 (D) Between 1 & 2

Last Answer : (C) < 1

The rated life of a bearing varies (a) directly as load (b) inversely as the square of the load (c) inversely as the cube of the load

Description : The rated life of a bearing varies (a) directly as load (b) inversely as the square of the load (c) inversely as the cube of the load

Last Answer : (c) inversely as the cube of the load

The rated life of a bearing varies A. Directly as load B. Inversely as square of load C. Inversely as cube of load D. Inversely as fourth power of load

Description : The rated life of a bearing varies A. Directly as load B. Inversely as square of load C. Inversely as cube of load D. Inversely as fourth power of load

Last Answer : C. Inversely as cube of load

The rated life of a bearing varies (A) Directly as load (B) Inversely as square of load (C) Inversely as cube of load (D) Inversely as fourth power of load

Description : The rated life of a bearing varies (A) Directly as load (B) Inversely as square of load (C) Inversely as cube of load (D) Inversely as fourth power of load

Last Answer : (C) Inversely as cube of load

Permeability of soil varies a) Inversely as square of grain size b) Inversely as grain size c) Directly as grain size d) Square of grain size*

Description : Permeability of soil varies a) Inversely as square of grain size b) Inversely as grain size c) Directly as grain size d) Square of grain size*

Last Answer : d) Square of grain size*

The gravitational potential energy of an object close to the ground varies: w) inversely as its distance from the ground x) directly as its distance from the ground y) inversely as the square of its distance from the ground z) directly as the square of its distance from the ground

Description : The gravitational potential energy of an object close to the ground varies: w) inversely as its distance from the ground x) directly as its distance from the ground y) inversely as the square of its distance from the ground z) directly as the square of its distance from the ground 

Last Answer : ANSWER: X -- DIRECTLY AS ITS DISTANCE FROM THE GROUND

The energy loss over a length of pipeline according to Darcy-Weisbach equation for pipe flow is ___________ the mean velocity of flow. (A) Directly proportional to (B) Directly proportional to square of (C) Inversely proportional to (D) Inversely proportional to square of

Description : The energy loss over a length of pipeline according to Darcy-Weisbach equation for pipe flow is ___________ the mean velocity of flow. (A) Directly proportional to (B) Directly proportional to square of (C) Inversely proportional to (D) Inversely proportional to square of

Last Answer : (B) Directly proportional to square of

The pressure of fluid due to hammer blow is (A) Directly proportional to density of fluid (B) Inversely proportional to density of fluid (C) Directly proportional to (density)1/2 of fluid (D) Inversely proportional to (density)1/2 of fluid

Description : The pressure of fluid due to hammer blow is (A) Directly proportional to density of fluid (B) Inversely proportional to density of fluid (C) Directly proportional to (density)1/2 of fluid (D) Inversely proportional to (density)1/2 of fluid

Last Answer : Answer: Option C

Heat transfer efficiency leading of energy conservation in a heat exchanger can be achieved by (A) Keeping the heat transfer surface clean (B) Enhancing the fluid pumping rate (C) Increasing the tube length (D) None of these

Description : Heat transfer efficiency leading of energy conservation in a heat exchanger can be achieved by (A) Keeping the heat transfer surface clean (B) Enhancing the fluid pumping rate (C) Increasing the tube length (D) None of these

Last Answer : (A) Keeping the heat transfer surface clean

Use of transverse baffles in a shell and tube heat exchanger is done to increase the (A) Rate of heat transfer (B) Flow velocity (C) Turbulence of shell side fluid (D) All (A), (B) and (C)

Description : Use of transverse baffles in a shell and tube heat exchanger is done to increase the (A) Rate of heat transfer (B) Flow velocity (C) Turbulence of shell side fluid (D) All (A), (B) and (C)

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

The periodic time of a body moving in Simple Harmonic Motion is a.Directly proportional to its angular velocity b.Directly proportional to the weight of the body c.Inversely proportional to the square of angular velocity d.Directly proportional to the momentum of swinging body e.Inversely proportional to the angular velocity

Description : The periodic time of a body moving in Simple Harmonic Motion is a.Directly proportional to its angular velocity b.Directly proportional to the weight of the body c.Inversely proportional to ... d.Directly proportional to the momentum of swinging body e.Inversely proportional to the angular velocity

Last Answer : e. Inversely proportional to the angular velocity

Let the only force acting on two bodies be their mutual interactions. If both bodies start from rest, the distances travelled by each will be a a.proportional to the respective masses of the bodies b.107 dynes c.inversely proportional to the respective masses of the bodies d.directly proportional to the square of the respective masses of the bodies e.inversely proportional to the square of the respective masses of the bodies

Description : Let the only force acting on two bodies be their mutual interactions. If both bodies start from rest, the distances travelled by each will be a a.proportional to the respective masses of the ... masses of the bodies e.inversely proportional to the square of the respective masses of the bodies

Last Answer : c. inversely proportional to the respective masses of the bodies

The velocity of sound is ….. the density of the medium. (a) Directly proportional to (b) Inversely proportional to (c) Directly proportional to the square root of (d) Inversely proportional to the square root of

Description : The velocity of sound is ….. the density of the medium. (a) Directly proportional to (b) Inversely proportional to (c) Directly proportional to the square root of (d) Inversely proportional to the square root of

Last Answer : Ans:(d)

The frequency of vibration of a stretched string is _______ its length. (a) Directly proportional to (b) Inversely proportional to (c) Directly proportional to the square of (d) Independent of

Description : The frequency of vibration of a stretched string is _______ its length. (a) Directly proportional to (b) Inversely proportional to (c) Directly proportional to the square of (d) Independent of

Last Answer : Ans:(b)

Boyle's law states that A. pressure of a gas is inversely proportional to its volume i.e. P × V = constant B. pressure of a gas is directly proportional to its volume i.e. P⁄V = constant C. pressure of a gas is inversely proportional to the square of its volume i.e. P × V² = constant D. pressure of a gas is directly proportional to the square of its volume i.e. P ⁄ V² = constant

Description : Boyle's law states that A. pressure of a gas is inversely proportional to its volume i.e. P V = constant B. pressure of a gas is directly proportional to its volume i.e. P⁄V = constant C. ... of a gas is directly proportional to the square of its volume i.e. P ⁄ V² = constant

Last Answer : pressure of a gas is inversely proportional to its volume i.e. P × V = constant

Assuming uniform density of the core, the acceleration due to gravity below the Earth's surface is A. inversely proportional to the square of the distance from the center of the Earth B. inversely proportional to the distance from the center of the Earth C. directly proportional to the square of the distance from the center of the Earth D. directly proportional to the distance from the center of the Earth

Description : Assuming uniform density of the core, the acceleration due to gravity below the Earth's surface is A. inversely proportional to the square of the distance from the center of the Earth ... center of the Earth D. directly proportional to the distance from the center of the Earth

Last Answer : directly proportional to the distance from the center of the Earth

The load shared by each spring is inversely proportional to the cross section of wire. a) Yes b) No, it is directly proportional c) It is proportional to its square d) It is proportional to its square root

Description : The load shared by each spring is inversely proportional to the cross section of wire. a) Yes b) No, it is directly proportional c) It is proportional to its square d) It is proportional to its square root

Last Answer : b) No, it is directly proportional

According to Newton's law of universal gravitation, any two particles of finite mass attract one another with a force which is A. Inversely proportional to the product of their masses and directly proportional to the square of their distance apart B. Inversely proportional to the product of their masses and directly proportional to their distance apart C. Directly proportional to the product of their masses and inversely proportional to their distance apart D. Directly proportional to the product of their masses and inversely proportional to the square of their distance apart

Description : According to Newton's law of universal gravitation, any two particles of finite mass attract one another with a force which is A. Inversely proportional to the product of their masses and ... the product of their masses and inversely proportional to the square of their distance apart

Last Answer : Directly proportional to the product of their masses and inversely proportional to the square of their distance apart

The strain energy due to volumetric strain (A) Is directly proportional to the volume (B) Is directly proportional to the square of exerted pressure (C) Is inversely proportional to Bulk modulus (D) All the above

Description : The strain energy due to volumetric strain  (A) Is directly proportional to the volume  (B) Is directly proportional to the square of exerted pressure  (C) Is inversely proportional to Bulk modulus  (D) All the above 

Last Answer : (D) All the above 

Degree of consolidation is (A) Directly proportional to time and inversely proportional to drainage path (B) Directly proportional to time and inversely proportional to square of drainage path (C) Directly proportional to drainage path and inversely proportional to time (D) Directly proportional to square of drainage path and inversely proportional to time

Description : Degree of consolidation is (A) Directly proportional to time and inversely proportional to drainage path (B) Directly proportional to time and inversely proportional to square of drainage path (C ... to time (D) Directly proportional to square of drainage path and inversely proportional to time

Last Answer : Answer: Option B

The coherence length over which there is a strong relationship between amplitudes is; (A) Directly proportional to the bandwidth (B) Inversely proportional to the bandwidth (C) The square of the bandwidth (D) None of these

Description : The coherence length over which there is a strong relationship between amplitudes is; (A) Directly proportional to the bandwidth (B) Inversely proportional to the bandwidth (C) The square of the bandwidth (D) None of these

Last Answer : Answer: Option B