Soldering is the process of which of the following?

• A. Engraving designs on metal
• B. Welding metal pieces together
• C. Joining two metals
• D. Polishing a metal surface

Answer: (C)

Soldering joins two metal pieces using a filler metal that has a lower melting point than the metals being joined. The solder melts and flows into the joint ( aided by flux and capillary action ), then cools to form a bond while the base metals remain solid. This distinguishes it from welding, where the base metals are melted to fuse them together. Engraving removes material to create designs, and polishing smooths a surface. So the action described is joining two metals.