1. 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
Explanation: 20:1 and less
2. 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
Explanation: For maximum power generation, the air fuel ratio for a petrol engine of vehicles, is of the order of 12:1
3. 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
Explanation: 9-10m3 volume of air is required for consuming 1 litre of fuel by a four stroke engine.
4. 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
Explanation: Petrol engine cannot work below air fuel ratio 20:1.
5. A stoichiometric air fuel ratio is ______________
a) chemically correct mixture
b) lean mixture
c) rich mixture for idling
d) rich mixture for over loads
Explanation: chemically correct mixture
6. Dissociation is the disintegration of burnt gases at __________ temperatures.
a) low
b) high
c) constant
d) none of the mentioned
Explanation: Dissociation is the disintegration of burnt gases at high temperatures
7. In lean mixtures no dissociation takes place at _____________ temperatures
a) low
b) high
c) constant
d) none of the mentioned
Explanation: In lean mixtures no dissociation takes place at low temperatures
8. In rich mixtures dissociation is prevented by the available ____________
a) CO
b) CO2
c) O2
d) CO and O2
Explanation: CO and O2
9. Power output is maximum at stoichiometric ratio where there is ____________
a) dissociation
b) no dissociation
c) rich mixture
d) none of the mentioned
Explanation: no dissociation
10. Maximum dissociation is for ____________
a) lean mixture
b) rich mixture
c) stoichiometric
d) none of the mentioned
Explanation: Maximum dissociation is for stoichiometric mixtures while in lean mixtures, generally no dissociation takes place.