Question

If arc length is shortened, metal transferring across the gap may short out the electrode, causing it to:

A) Overheat

B) Lengthen

C) Harden

D) Melt

Answer 1

Shortening the arc length in welding can cause the electrode to melt due to an increase in temperature resulting from lower resistance and higher power dissipation in the circuit.

Step-by-step explanation:

If the arc length is shortened during a welding process, metal transferring across the gap may cause the electrode to melt. This is due to the fact that the shortened arc leads to an increase in temperature as a result of lower resistance in the electrical circuit. As per Ohm's Law, the power dissipation is represented by P = V2/r, meaning that as resistance decreases, the power dissipation increases, which causes higher temperatures. This can lead to further ionization and increase in power dissipation, creating a hazardous cycle that results in the melting of the electrode, especially when high voltages are used.