Question

What are the electrodes used in the resistance furnace for the formation of $SiC$ ?
A. Iron
B. Carbon
C. Platinum
D. Gold

Answer 1

A resistance furnace is an example of electric furnace that utilizes electricity to produce a heated enclosed chamber for carrying out reactions that require drastic conditions of temperature and pressure.

Complete answer:
High temperatures processes like alloy formation and melting of metals are carried out in an electricity run chamber of heat called the resistance furnaces.
Resistance to the flow of electricity is due to the barriers faced by charge carriers (usually electrons). On facing resistance the electrons experience a decrease in mobility and create a heating effect. Thus the entire chemical energy coming from the electrodes is not converted to electrical energy but a bigger part of it is dissipated as heat.
Resistance furnaces utilize this phenomenon of heating effect to carry out the formation of silicon carbides. The material that is charged inside the furnace itself acts as the heating element. The electrodes that are dipped in metal to carry out the process are made up of iron and an allotrope of carbon called graphite.
Thus, the correct options are (A) and (B) as both iron and carbon electrodes are used in the formation of silicon carbides.

Note:
The electricity supplied to the furnace does not play any electrochemical role (i.e. does not carry out the oxidation or reduction of any chemical species) and is simply used as a power source of uniformly heating the chamber.