(i) What are the basic differences between arc welding and submerged arc welding?
(ii) What are the inert gases generally used in inert gas arc welding?
(iii) What is weld penetration and what is weld reinforcement?
(iv) In MIG welding the power source characteristic is
VP = 36- $\frac{I}{60}$ and the arc characteristic is
Va = 2la + 27
where VP and Va voltage, I current, la arc length in mm.
Find the change in power of the arc if the arc length is changed from 2mm to 4 mm.
If the maximum current capacity of the power source is 360 amps, find the minimum arc length sustainable?