Question

Statement (I): A good CI engine fuel, like diesel oil, is a bad SI engine fuel and a good SI engine fuel, like petrol. is a bad Cl engine fuel.

Statement (II): A good CI engine fuel requires high self-ignition temperature and a good SI engine fuel requires low self-ignition temperature.
1. Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
2. Both Statement (I) and Statement (II) are individually true and Statement (II) is NOT the correct explanation of Statement (I)
3. Statement (I) is true but Statement (II) false 
4. Statement (I) is false but Statement (II) is true 

Answer 1

Correct Answer - Option 3 : Statement (I) is true but Statement (II) false 

Explanation:

A good CI fuel like diesel oil requires high self-ignition temperature when it is used in SI engines which are not achieved in SI engine due to this unburnt fuel particles are left inside the engine block so it is not a good fuel for SI engines.

Similarly, a good SI fuel like petrol requires a high self-ignition temperature to avoid knocking before normal combustion occurs.

And for CI engine, a low self-ignition temperature is required as it starts combustion by the only compression.

So, statement 1 is true and statement 2 is false.