Chemical Engineering

If Prandtl number is greater than the Schmidt number, then the

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Question: If Prandtl number is greater than the Schmidt number, then the
[A].

thermal boundary layer lies inside the concentration boundary layer.

[B].

concentration boundary layer lies inside the thermal boundary layer.

[C].

thermal & concentration boundary layers are of equal thickness.

[D].

hydrodynamic(i.e., momentum)boundary layer is thicker than the other two.

Answer: Option A

Explanation:

No answer description available for this question.

For a laminar flow of fluid in a circular tube, ‘h1’ is the convective heat transfer co-efficient at velocity ‘V1’. If the velocity is reduced by half and assuming the fluid properties are constant, the new convective heat transfer co-efficient is

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Question: For a laminar flow of fluid in a circular tube, ‘h1’ is the convective heat transfer co-efficient at velocity ‘V1’. If the velocity is reduced by half and assuming the fluid properties are constant, the new convective heat transfer co-efficient is
[A].

1.26 h1

[B].

0.794 h1

[C].

0.574 h1

[D].

1.741 h1

Answer: Option B

Explanation:

No answer description available for this question.

For turbulent flow in a tube, the heat transfer co-efficient is obtained from the Dittus-Boelter correlation. If the tube diameter is halved and the flow rate is doubled, then the heat transfer co-efficient will change by a factor of

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Question: For turbulent flow in a tube, the heat transfer co-efficient is obtained from the Dittus-Boelter correlation. If the tube diameter is halved and the flow rate is doubled, then the heat transfer co-efficient will change by a factor of
[A].

1

[B].

1.74

[C].

6.1

[D].

37

Answer: Option C

Explanation:

No answer description available for this question.

A composite flat wall of a furnace is made of two materials ‘A’ and ‘B’. The thermal conductivity of ‘A’ is twice of that of material ‘B’, while the thickness of layer of ‘A’ is half that of B. If the temperature at the two sides of the wall are 400 and 1200°K, then the temperature drop (in °K) across the layer of material ‘A’ is

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Question: A composite flat wall of a furnace is made of two materials ‘A’ and ‘B’. The thermal conductivity of ‘A’ is twice of that of material ‘B’, while the thickness of layer of ‘A’ is half that of B. If the temperature at the two sides of the wall are 400 and 1200°K, then the temperature drop (in °K) across the layer of material ‘A’ is
[A].

125

[B].

133

[C].

150

[D].

160

Answer: Option D

Explanation:

No answer description available for this question.

In an interphase heat transfer process, the equilibrium state corresponds to equality of temperature in the two phases, while the condition for equilibrium in an interphase mass transfer process is equality of

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Question: In an interphase heat transfer process, the equilibrium state corresponds to equality of temperature in the two phases, while the condition for equilibrium in an interphase mass transfer process is equality of
[A].

concentrations

[B].

chemical potentials

[C].

activity co-efficients

[D].

mass transfer co-efficients

Answer: Option A

Explanation:

No answer description available for this question.

A multiple effect evaporator as compared to a single effect evaporator of the same capacity has

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Question: A multiple effect evaporator as compared to a single effect evaporator of the same capacity has
[A].

lower heat transfer area.

[B].

lower steam economy.

[C].

higher steam economy.

[D].

higher solute concentration in the product.

Answer: Option C

Explanation:

No answer description available for this question.