Question 268Motor Plants - Assistant Engineer

70% to pass

A mixture of 45% cetane and 55% alpha-methyl-naphthalene is found to have the same ignition delay as a sample of diesel oil. The sample can be described as having a/an _______________.

Acetane number of 55
Bcetane number of 45
Coctane number of 55
Doctane number of 45
AI Explanation

The correct answer is B) cetane number of 45. The cetane number is a measure of the ignition quality of a fuel, with higher cetane numbers indicating better ignition and combustion characteristics. Since the given mixture has the same ignition delay as diesel oil, it can be described as having a cetane number of 45, which is the typical cetane number range for diesel fuels. The other options are incorrect because: A) A cetane number of 55 would indicate a higher ignition quality than the diesel oil sample. C) The octane number is a measure of the antiknock properties of a fuel, which is not relevant for this diesel fuel mixture. D) A cetane number of 45 is more accurate than 55 for describing the ignition characteristics of the given mixture.

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Official Resources
46 CFR Machinery & Electrical 46 CFR Engineering USCG National Maritime Center
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