Practice question

What is the physical significance of the cetane rating of a diesel fuel?

It measures the fuel's chemical resistance to pre-ignition knocking in petrol engines.
It measures the ignition delay period of the fuel; a higher cetane number indicates a shorter ignition delay.
It indicates the fuel's volatility and evaporation rate under atmospheric conditions.
It measures the percentage of lead compounds and sulfur in the fuel.

Answer: B — It measures the ignition delay period of the fuel; a higher cetane number indicates a shorter ignition delay.

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