What were the two discoveries of Sir Humphrey Davy that led to the development of modern welding technology?

What is meant by the term faying surface?

Define the term fusion weld.

What is the fundamental difference between a fusion weld and a solid state weld?

What is an autogenous weld?

Name and sketch the five joint types.

Define and sketch a fillet weld.

Define and sketch a groove weld.

Why is a surfacing weld different from the other weld types?

Why is it desirable to use energy sources for welding that have high heat densities?

What is the unit melting energy in welding, and what are the factors on which it depends?

Define and distinguish the two terms heat transfer factor and melting factor in welding.

What is the heat-affected zone (HAZ) in a fusion weld?