Engineering :: Heat Transfer

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11.

Heat is transferred by conduction, convection and radiation in

A.	Insulated pipes carrying hot water	B.	Refrigerator freezer coils
C.	Melting of ice	D.	Boiler furnaces
E.	Condensation of steam in a condenser

12.

Transient heat flow occurs in

A.	Electric conductors carrying current	B.	Insulated pipes carrying superheated steam
C.	Cooling of casting	D.	Heating and cooling of buildings due to sun
E.	Melting of ice

13.

Molecular transmission of heat is smallest in case of

14.

Essential requirement for the transfer of heat from one body to another is

A.	Both bodies must be solids	B.	Both bodies must be in contact
C.	Temperatures of the two bodies must be different	D.	One of the bodies must have internal source of heat generation
E.	All of the above

15.

?40?C is equivalent to

16.

The temperature inside a furnace is generally measured by

17.

The rate of heat flow from a 50 mm thick wall of material having thermal conductivity of 40 W/m?C for a temperature difference of 10?C will be

18.

Pipes are insulated so that

A.	They may not break under pressure	B.	There is minimum corrosion
C.	They can withstand higher fluid pressures	D.	Heat loss from the surface is minimized
E.	Vibrations resulting from fluid flow are minimized

19.

All heat transfer processes

A.	Involve transfer of energy	B.	Involve temperature difference between the bodies
C.	Obey first law of thermodynamics	D.	Obey second law of thermodynamics
E.	Obey Newton's law

20.

Steady state heat transfer occurs when

A.	The flow of heat is negligible	B.	The flow of heat is uniform
C.	The flow of heat is independent of time	D.	The flow of heat is uniformly increasing
E.	The flow of heat is uniformly decreasing