Heat Transfer

The amount of heat flow through a body by conduction is

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Question: The amount of heat flow through a body by conduction is
[A].

directly proportional to the surface area of the body

[B].

directly proportional to the temperature difference on the two faces of the body

[C].

inversely proportional to the thickness of the body

[D].

all of the above

Answer: Option D

Explanation:

No answer description available for this question.

Fourier’s law of heat conduction is (where Q = Amount of heat flow through the body in unit time, A = Surface area of heat flow, taken at right angles to the direction of heat flow, dT = Temperature difference on the two faces of the body, dx = Thickness of the body, through which the heat flows, taken along the direction of heat flow, and k = Thermal conductivity of the body)

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Question: Fourier’s law of heat conduction is (where Q = Amount of heat flow through the body in unit time, A = Surface area of heat flow, taken at right angles to the direction of heat flow, dT = Temperature difference on the two faces of the body, dx = Thickness of the body, through which the heat flows, taken along the direction of heat flow, and k = Thermal conductivity of the body)
[A].

[B].

[C].

[D].

Answer: Option A

Explanation:

No answer description available for this question.

Conduction is the process of heat transfer from one particle of the body to another by the actual motion of the heated particles.

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Question: Conduction is the process of heat transfer from one particle of the body to another by the actual motion of the heated particles.
[A].

True

[B].

False

Answer: Option B

Explanation:

No answer description available for this question.

Conduction is a process of heat transfer

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Question: Conduction is a process of heat transfer
[A].

from one particle of the body to another without the actual motion of the particles

[B].

from one particle of the body to another by the actual motion of the heated particles.

[C].

from a hot body to a cold body, in a straight line, without affecting the intervening medium

[D].

none of the above

Answer: Option A

Explanation:

No answer description available for this question.

In Joule’s experiment, an insulated container contains 20 kg of water initially at 25°C. It is stirred by an agitator, which is made to turn by a slowly falling body weighing 40 kg through a height of 4 m. The process is repeated 500 times. The acceleration due to gravity is 9.8 ms-2. Neglecting the heat capacity of agitator, the temperature of water (in °C) is

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Question: In Joule’s experiment, an insulated container contains 20 kg of water initially at 25°C. It is stirred by an agitator, which is made to turn by a slowly falling body weighing 40 kg through a height of 4 m. The process is repeated 500 times. The acceleration due to gravity is 9.8 ms-2. Neglecting the heat capacity of agitator, the temperature of water (in °C) is
[A].

40.5

[B].

34.4

[C].

26.8

[D].

25

Answer: Option B

Explanation:

No answer description available for this question.

A long iron rod initially at a temperature of 20°C has one end dipped in boiling water (100°C) at time, t = 0. The curved surface of the rod is insulated so that heat conduction is one dimensional in the axial direction. The temperature at a distance 100 mm from the dipped end becomes 40°C at time, t = 200 s. The same temperature is achieved at a distance of 200 mm from the dipped end at time

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Question: A long iron rod initially at a temperature of 20°C has one end dipped in boiling water (100°C) at time, t = 0. The curved surface of the rod is insulated so that heat conduction is one dimensional in the axial direction. The temperature at a distance 100 mm from the dipped end becomes 40°C at time, t = 200 s. The same temperature is achieved at a distance of 200 mm from the dipped end at time
[A].

t = 283 s

[B].

t = 356 s

[C].

t = 400 s

[D].

t = 800 s

Answer: Option D

Explanation:

No answer description available for this question.

A composite wall consists of two plates A and B placed in series normal to the flow of heat. The thermal conductivities are kA and kB and the specific heat capacities are CPA and CPB for plates A and B respectively. Plate B has twice the thickness of plate A. At steady state, the temperature difference across plate A is greater than that across plate B, when

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Question: A composite wall consists of two plates A and B placed in series normal to the flow of heat. The thermal conductivities are kA and kB and the specific heat capacities are CPA and CPB for plates A and B respectively. Plate B has twice the thickness of plate A. At steady state, the temperature difference across plate A is greater than that across plate B, when
[A].

CPA > CPB

[B].

CPA < CPB

[C].

kA < 0.5kB

[D].

kA>2 kB

Answer: Option C

Explanation:

No answer description available for this question.

Fresh orange juice contains 12% (by weight) solids and the rest water 90% of the fresh juice is sent to an evaporator to remove water and subsequently mixed with the remaining 10% of fresh juice. The resultant product contains 40% solids. The kg of water removed from 1 kg fresh juice is

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Question: Fresh orange juice contains 12% (by weight) solids and the rest water 90% of the fresh juice is sent to an evaporator to remove water and subsequently mixed with the remaining 10% of fresh juice. The resultant product contains 40% solids. The kg of water removed from 1 kg fresh juice is
[A].

0.4

[B].

0.5

[C].

0.6

[D].

0.7

Answer: Option D

Explanation:

No answer description available for this question.