Correct option is B
Spot welding is a type of
resistance welding in which
heavy current (up to 50,000A) is passed through the workpieces at the joint. The heat generated by the electrical resistance at the contact points between the metal sheets causes localized melting, and external pressure is applied to create a solid joint. This process is widely used for joining
thin sheets of metal, especially in automotive and sheet metal industries.
Arc welding uses an electric arc to generate high heat for melting and joining metals.
The current in arc welding is much lower than in spot welding, typically ranging between
100-300A. It does not rely on external pressure to form the joint, as it is a fusion welding process.
Gas welding uses a flame produced by burning gases like acetylene and oxygen to melt and join metals.
It is a slower process compared to spot welding and does not involve the use of high currents or external pressure.
