Computer Programming MCQs

5739 MCQs  (Page 210 of 574)

Radiant heating is used for which of the following ?
A. Annealing of metals
B. Melting of ferrous metals
C. Heating of liquids in electric kettle
D. Drying of paints and varnishes
Which of the following is an advantage of eddy current heating ?
A. The amount of heat generated can be controlled accurately
B. Heat at very high rate can be gene-rated
C. The area of the surface over which heat is produced can be accurately controlled
D. All of the above
Direct arc furnaces have which of the following power factors ?
A. Unity
B. Low, lagging
C. Low, leading
D. Any of the above
Which of the following devices is necessarily required for automatic temperature control in a furnace ?
A. Thermostat
B. Thermocouple
C. Auto-transformer
D. Heating elements of variable resis-tance material
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
Hysteresis loss and eddy current loss are used in____________?
A. Induction heating of steel
B. Dielectric heating
C. Induction heating of brass
D. Resistance heating
In arc furnace the function of choke is______________?
A. To stabilize the arc
B. To imprpve, power factor
C. To reduce severity of the surge
D. None of the above
Which of the following methods is used to control temperature in resistance furnaces ?
A. Variation of resistance
B. Variation of voltage
C. Periodical switching on and off of the supply
D. All of the above methods