Which term describes a fuel/air mixture with insufficient fuel?

Which term describes a fuel/air mixture with insufficient fuel?

• A. Too Rich
• B. Too Lean
• C. Normal
• D. Stoichiometric

Answer: (B)

Fuel and air must be in the right balance for combustion. When there isn’t enough fuel relative to the air, the mixture has excess air and is described as too lean. This means there isn’t enough fuel to sustain a flame, so ignition can be difficult or the flame may not propagate. The term captures exactly what “insufficient fuel” means. In contrast, too rich means there’s too much fuel for the air, stoichiometric is the exact perfect balance for complete combustion, and normal isn’t a standard technical descriptor for fuel/air mixtures.

Fuel and air must be in the right balance for combustion. When there isn’t enough fuel relative to the air, the mixture has excess air and is described as too lean. This means there isn’t enough fuel to sustain a flame, so ignition can be difficult or the flame may not propagate. The term captures exactly what “insufficient fuel” means. In contrast, too rich means there’s too much fuel for the air, stoichiometric is the exact perfect balance for complete combustion, and normal isn’t a standard technical descriptor for fuel/air mixtures.