The quality of petrol is expressed by:
- ACetane number
- BOctane number
- CButane number
- DReynolds number
- ENone of the above/More than one of the above
Show answer and explanation
Correct answer: (b) Octane number
Explanation
The quality of petrol is given by its octane number: its resistance to knocking (early ignition) in the engine, measured against iso-octane (100) and n-heptane (0).
Diesel is graded by its cetane number. The Reynolds number belongs to fluid flow.