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.Management Sciences
Category: Heating and Welding
Resistance variation method of temperature control is done by connecting resistance elements in_____________?
A. series
B. parallel
C. series-parallel connections
D. star-delta connections
E. all of the above ways
A non-dimensional number generally associated with natural convection heat transfer is____________?
A. Prandtl number
B. Grashoff number
C. Pecelet number
D. Nusselt number
method has leading power factor____________?
A. Resistance heating
B. Dielectric heating
C. Arc heating
D. Induction heating
In heating the ferromagnetic material by induction heating, heat is produced due to_____________?
A. induced current flow through the charge
B. hysteresis loss taking place below curie temperature
C. due to hysteresis loss as well as eddy current loss takingplace in the charge
D. none of the above factors
Properly of low temperature co-eflficient of heating element is desired due to which of the following reasons ?
A. To avoid initial rush of current
B. To avoid change in kW rating with temperature
C. Both (A) and (B)
D. Either (A) or (B)
The material of the heating element for a furnace should have___________?
A. lower melting point
B. higher temperature coefficient
C. high specific resistance
D. all of the above
Induction heating process is based on which of the following principles ?
A. Thermal ion release principle
B. Nucleate heating principle
C. Resistance heating principle
D. Electro-magnetic induction princi¬ple
Which of the following insulating materials was suitable for low temperature applications ?
A. Asbestos paper
B. Diatomaceous earth
C. 80 percent magnesia
D. Cork
Induction furnaces are employed for which of the following ?
A. Heat treatment of castings
B. Heating of insulators
C. Melting aluminium
D. None of the above
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