The process of heat transfer during the reentry of satellites and missiles, at very high speeds, into earth’s atmosphere is known as ?
A. ablation
B. radiation
C. viscous dissipation
D. irradiation
A. ablation
Heating and Welding MCQs
Heating and Welding MCQs. Multiple Choice Questions and Answers relating to hot work, welding, etc in Electrical Engineering.
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 principle
D. Electro-magnetic induction principle
Heat transfer by condition will not occur when ?
A. bodies are kept in vacuum
B. bodies are immersed in water
C. bodies are exposed to thermal radiations
D. temperatures of the two bodies are identical
D. temperatures of the two bodies are identical
Which of the following has the highest value of thermal conductivity ?
A. Water
B. Steam
C. Sold ice
D. Melting ice
C. Sold ice
A non-dimensional number generally associated with natural convection heat transfer is ?
A. Prandtl number
B. Grashoff number
C. Pecelet number
D. Nusselt number
B. Grashoff number
Which of the following will happen if the thickness of refractory wall of furnace is increased ?
A. Heat loss through furnace wall will increase
B. Temperature inside the furnace will fall
C. Temperature on the outer surface of furnace walls will drop
D. Energy consumption will increase
C. Temperature on the outer surface of furnace walls will drop
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
A. Heat treatment of castings
In a resistance furnace the atmosphere is ?
A. oxidizing
B. deoxidising
C. reducing
D. neutral
A. oxidizing
In induction heating ___________ is abnormally high ?
A. phase angle
B. frequency
C. current
D. voltage
B. frequency
By which of the following methods the temperature inside arcane can be varied ?
A. By disconnecting some of the heating elements
B. By varying the operating voltage
C. By varying the current through heating elements
D. By any of the above method
D. By any of the above method