Question

Carbon electrodes are used in:

1. GLS lamps

2. Dry cells

3. Arc furnace

1. 1, 2 and 3
2. 2 and 3
3. 1 and 3
4. Only 1

Answer 1

Correct Answer - Option 2 : 2 and 3

Dry cell

• A dry cell consists of a metal container in which a low moisture electrolyte paste covers the graphite rod or a metal electrode. Generally, the metal container will be zinc whose base acts as a negative electrode (anode) and a carbon road acts as a positive electrode (cathode). It is surrounded by manganese dioxide and low moisture electrolytes like ammonium chloride paste, which will produce a maximum of 1.5V of voltage, and they are not reversible.
• These are popular batteries used nowadays on laptops, iPods, cellphones.
• The electrodes of the cell are made up of lightweight carbon and lithium

Electric Arc Furnace

• In this, an electric arc is produced between the electrodes. This electric arc is used for melting the metal.
• Usually, the carbon and graphite electrodes are used, and they can be selected based on their electrical conductivity, insolubility, chemical inertness, mechanical strength, resistance to thermal shock, etc.
• The carbon electrodes are used with small furnaces for the manufacturing of ferro-alloys, aluminum phosphorous, etc.

GLS lamps

• Normally, inert gases like argon is used to fill GLS lamps.