250+ TOP MCQs on Fuel Air Cycle and Answers

IC Engines Multiple Choice Questions on “Fuel Air Cycle”.

1. The air fuel ratio of the petrol engine is controlled by ____________
a) fuel pump
b) governor
c) injector
d) carburettor
Answer: d
Clarification: The air fuel ratio of the petrol engine is controlled by carburettor and not by injector or fuel pump.

2. Fuel consumption of diesel engines is not guaranteed at one quarter load because at such low loads ____________
a) the friction is high
b) the friction is unpredictable
c) the small difference in cooling water temperature or in internal friction has a disproportionate effect
d) the engine is rarely operated
Answer: c
Clarification: None.

3. The fuel air ratio in a petrol engine fitted with suction carburettor, operating with dirty air filter as compared to clean filter will be ____________
a) higher
b) lower
c) remain unaffected
d) none of the mentioned
Answer: a
Clarification: None.

4. The theoretically correct air fuel ratio for petrol engine is of the order of ____________
a) 6:1
b) 9:1
c) 12:1
d) 15:1
Answer: d
Clarification: None.

5. Air fuel ratio for idling speed of a petrol engine is approximately ____________
a) 1:1
b) 5:1
c) 10:1
d) 15:1
Answer: c
Clarification: None.

6. Air fuel ratio at which a petrol engine can not work is?
a) 8:1
b) 10:1
c) 15:1
d) 20:1 and less
Answer: d
Clarification: None.

7. For maximum power generation, the air fuel ratio for a petrol engine of vehicles, is of the order of ____________
a) 9:1
b) 12:1
c) 15:1
d) 18:1
Answer: b
Clarification: None.

8. The following volume of air is required for consuming 1 litre of fuel by a four stroke engine is?
a) 1m³
b) 2.5m³
c) 5-6m³
d) 9-10m³
Answer: d
Clarification: 9-10m³ volume of air is required for consuming 1 litre of fuel by a four stroke engine.

9. Diesel engine can work on very lean air fuel ratio of the order of 30:1. A petrol engine can also work on such a lean ratio provided?
a) it is properly designed
b) best quality fuel is used
c) can not work as it is impossible
d) flywheel size is proper
Answer: c
Clarification: Petrol engine cannot work below air fuel ratio 20:1.

10. A stoichiometric air fuel ratio is ____________
a) chemically correct mixture
b) lean mixture
c) rich mixture for idling
d) rich mixture for over loads
Answer: a
Clarification: None.