What happens when an appliance's primary air supply is significantly reduced?

Question: What happens when an appliance's primary air supply is significantly reduced?

Answer options: ✅ The flame will become lazy and yellow, potentially producing soot.

• The flame will become sharp and blue, increasing efficiency.
• The flame will extinguish immediately.
• The gas pressure to the burner will increase.

Correct answer: The flame will become lazy and yellow, potentially producing soot.

Explanation: Insufficient primary air leads to incomplete combustion, characterized by a lazy, yellow flame and the potential for soot and carbon monoxide.