An electric furnace producing heat by means of an electric arc struck between each of three electrodes and the charge is called ____________ furnace?

Related Mcqs:

1. In a furnace, the heat taken by the charge/stock and the heat lost to the furnace structure & flue gases depends on the__________________?

   A. Rate of firing and emissivity of flame
   B. Thermal conductivity of the charge & structural materials of furnace
   C. Nature of process; whether batch, continuous or intermittent
   D. All A., B. and C.

2. The electric furnace in which heat is produced by a combination of induced current and skin effect is called _____________ furnace?

   A. Arc
   B. Resistance
   C. Low frequency induction
   D. High frequency induction

3. While the fuel fired furnace can be used upto a maximum temperature of about 1700°C, the electric furnace can be used upto a temperature of about _____________ °C?

   A. 2000
   B. 3000
   C. 4500
   D. 6000

4. _____________ furnace is not an electric furnace?

   A. Arc
   B. Induction
   C. Pot
   D. Resistance

5. Combustion of furnace oil in a furnace (soaking pit) with preheated combustion air at 400°C results in saving of about __________ percent furnace oil as compared to its combustion with atmospheric air, if the flue gas outlet temperature from the soaking pit is 1200°C ?

   A. 5
   B. 60
   C. 20
   D. 40

6. In salt bath furnace, heat is transferred to the charge mainly by __________________?

   A. Conduction
   B. Convection
   C. Radiation
   D. None of these

7. Heat transfer rate to the stock/charge in the furnace does not depend upon the________________?

   A. Emissivity of the refractory walls
   B. Size of the furnace
   C. Use of waste heat recovery equipments
   D. Thickness of the stock

8. Heat transfer rate to the charge/stock in a furnace does not depend upon the________________?

   A. Type of fuels viz. solid, liquid or gaseous
   B. Flue gas temperature
   C. Emissivity of refractory walls
   D. Initial temperature of the charged stock

9. Ceramic coating material for furnace refractory, which increases its emissivity and thus the radiation heat transfer rate in the furnace, comprises of_________________?

   A. Graphite powder
   B. Thoria
   C. Zircon powder
   D. Beryllium

10. Rate of heat release in a furnace, which is the measure of heat intensity, is defined as_________________?

    A. kcal/hr/m3 combustion space
    B. kcal/m3 combustion space
    C. kcal/hr
    D. None of these