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The resistance furnace produces heat by the__________________? A. Electric arc struck between electrodes and the chargeB. Flow of current through a heating element C. Combination of induced current and skin effect D. None of these
Thickness of stock does not affect the fuel economy of furnaces, if the material to be heated is of__________________? A. Low emissivity B. High thermal conductivityC. Both A. and B. D. Neither A. nor B.
An example of indirectly heated furnace is the_________________? A. Soaking pitB. Muffle furnace C. Reheating furnace D. None of these
Neutral atmosphere is maintained in a/an ____________ furnace? A. Cold rolled steel coil annealing B. Open hearth C. Soaking pit D. Walking beam reheating
The thermal efficiency of a steel slab reheating furnace (walking beam type) may be about ____________ percent? A. 15B. 40 C. 70 D. 85
In low or standard frequency induction furnace, heat is produced by the_______________________? A. Combination of induced current and skin effectB. Induction and resistance C. Current flow through a heating element D. None of these
The rate of scaling of furnace stock depends upon the_________________? A. Temperature B. Time C. Nature of atmosphereD. All A., B. and C.
The reason for excessive clinker formation in gas producers is the_____________________? A. Use of coal/coke containing a high % of fines and ash B. Use of fuel having too low an ash fusion temperature C. Development of hot spots in the fuel bed and an abnormally high rate of gasificationD. All A., B. and C.
In furnaces operating at very high temperature (say) 1250°C, e.g. soaking pit), the maximum heat transfer takes place by__________________? A. Conduction B. ConvectionC. Radiation D. Cannot be predicted
Amount of coal lost in ash particle, which is carried through the boiler system, depends upon the__________________? A. Physical nature, ash content and fineness of the coal B. Amount of excess air supplied and load on the boiler C. Type of burner and combustion chamberD. All A., B. and C.