Question
What is the characteristic appearance of a cold tin-lead solder joint?
Answer Options
- A) Dark black spots
- B) A bright or shiny surface
- C) A rough or lumpy surface
- D) Excessive solder
Correct Answer: C
Explanation
A proper solder joint should be heated correctly and then allowed to cool without disturbance, resulting in a smooth, bright, and shiny surface that indicates a good mechanical and electrical connection. A cold solder joint occurs when the heat was insufficient or the joint was disturbed during cooling.
The characteristic appearance of a cold solder joint is a rough or lumpy surface with a dull or grainy texture. These joints are unreliable; they often have high resistance, may fail electrically under vibration or temperature changes, and must be reheated and redone to ensure a sound connection.
This topic was automatically created to facilitate community discussion about this exam question. Feel free to share study tips, memory tricks, or additional explanations!