Which component is primarily responsible for atomizing diesel fuel before it enters the combustion chamber?

• A. Fuel injector nozzle
• B. Carburetor
• C. Piston
• D. Spark plug

Answer: (A)

Atomization of diesel fuel is achieved by the injector nozzle. In a diesel engine, fuel is pumped at very high pressure through the nozzle, where it is forced through tiny orifices to create a fine spray as it enters the combustion chamber. This small droplet spray mixes rapidly with the hot compressed air, allowing quick vaporization and efficient ignition under compression.

A carburetor wouldn’t provide this direct, high-pressure atomization and is not used in diesel engines. The piston is just the moving part inside the cylinder and does not atomize fuel, while the spark plug is used in spark-ignition engines to ignite the air–fuel mixture and is not involved in atomizing diesel fuel.