A designer chooses the values of fluid flow rates and specific heats in such a manner that the heat capacities of the two fluids are equal. A hot fluid enters the counter flow heat exchanger at 100°C and leaves at 60°C. A cold fluid enters the heat exchanger at 40°C. The mean temperature difference between the two fluids is

Heat and Mass Transfer
A designer chooses the values of fluid flow rates and specific heats in such a manner that the heat capacities of the two fluids are equal. A hot fluid enters the counter flow heat exchanger at 100°C and leaves at 60°C. A cold fluid enters the heat exchanger at 40°C. The mean temperature difference between the two fluids is

60°C

20°C

40°C

66.7°C

60°C

20°C

40°C

66.7°C

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
According of Kirchhoff's law

Emissive power and absorptivity are constant for all bodies

Radiant heat is proportional to fourth power of absolute temperature

Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body

Emissive power depends on temperature

Emissive power and absorptivity are constant for all bodies

Radiant heat is proportional to fourth power of absolute temperature

Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body

Emissive power depends on temperature

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
The total radiation from a black body per second per unit area is ________ fourth power of the absolute temperature. This statement is known as Stefan Boltzmann law.

Inversely proportional to

Equal to

None of these

Directly proportional to

Inversely proportional to

Equal to

None of these

Directly proportional to

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
In a shell and tube heat exchanger, baffles are provided on the shell side to

Prevent stagnation of shell side fluid

Improve heat transfer

Provide support for tubes

All of these

Prevent stagnation of shell side fluid

Improve heat transfer

Provide support for tubes

All of these

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
Depending on the radiating properties, a body will be black when(Where a = absorptivity, p = reflectivity, X = transmissivity.)

P = 0, x = 0 and a = 1

X = 0, a + p = 0

P = 0, x = 1 and a = 0

P= 1, T = 0 and a = 0

P = 0, x = 0 and a = 1

X = 0, a + p = 0

P = 0, x = 1 and a = 0

P= 1, T = 0 and a = 0

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
The critical radius is the insulation radius at which the resistance to heat flow is

Zero

Maximum

None of these

Minimum

Zero

Maximum

None of these

Minimum

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer

Heat and Mass Transfer According of Kirchhoff's law

Heat and Mass Transfer The total radiation from a black body per second per unit area is ________ fourth power of the absolute temperature. This statement is known as Stefan Boltzmann law.

Heat and Mass Transfer In a shell and tube heat exchanger, baffles are provided on the shell side to

Heat and Mass Transfer Depending on the radiating properties, a body will be black when(Where a = absorptivity, p = reflectivity, X = transmissivity.)

Heat and Mass Transfer The critical radius is the insulation radius at which the resistance to heat flow is

Heat and Mass Transfer
According of Kirchhoff's law

Heat and Mass Transfer
The total radiation from a black body per second per unit area is ________ fourth power of the absolute temperature. This statement is known as Stefan Boltzmann law.

Heat and Mass Transfer
In a shell and tube heat exchanger, baffles are provided on the shell side to

Heat and Mass Transfer
Depending on the radiating properties, a body will be black when(Where a = absorptivity, p = reflectivity, X = transmissivity.)

Heat and Mass Transfer
The critical radius is the insulation radius at which the resistance to heat flow is