A. Indirect arc furnace
B. Core less furnace
C. Either of the above
D. None of the above
Related Mcqs:
- 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 - By the use of which of the following, high frequency power supply for induction furnaces can be obtained ?
A. Coreless transformers
B. Current transformers
C. Motor-generator set
D. Multi-phase transformer - 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 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 - It is desirable to operate the arc furnaces at power factor of_____________?
A. zero
B. 0.707 lagging
C. unity
D. 0.707 leading - Which of the following insulating materials was suitable for low temperature applications ?
A. Asbestos paper
B. Diatomaceous earth
C. 80 percent magnesia
D. Cork - Which of the following is an advantage of heating by electricity ?
A. Quicker operation
B. Higher efficiency
C. Absence of flue gases
D. All of the above - Which of the following heating methods has maximum power factor ?
A. Arc heating
B. Dielectric heating
C. Induction heating
D. Resistance heating - By which of the following methods the temperature inside arc nace 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 - The temperature inside a furnace is usually measured by which of the following ?
A. Optical pyrometer
B. Mercury thermometer
C. Alcohol thermometer
D. Any of the above
