A. correct fuel air ratio
B. proper ignition temperature
C. 02 to support combustion
D. all the three above
E. none of the above
Related Mcqs:
- The specific fuel consumption for a petrol engine first decreases with increase in fuel air ratio and then increases with further increase in fuel air ratio. The minimum value occurs in the range of__________________?
A. lean mixture
B. chemically correct mixture
C. rich mixture
D. unpredictable
E. none of the above - Heating value of fuel used is as on fired basis. If it is reported for dry or moisture free fuel, then latter should be multiplied by the following factor to correct for as fired value ___________________?
A. (1- moisture content)
B. (1 + moisture content)
C. 1 + moisture content
D. 1 – moisture content - Which is correct statement about reaction time for autoignition of fuel and the fuel air ratio__________________?
A. lean mixture has high reaction time
B. rich mixture has high reaction time
C. chemically correct mixture has mini-mum reaction time
D. all of the above
E. non of the above - Auto-ignition reaction time for petrol engine first decreases with increase in fuel air ratio, reaches a minimum value and then increases with subsequent increase in fuel air ratio. The minimum value occurs in the region of________________?
A. Lean mixture
B. Chemically correct fuel air ratio
C. Rich mixture
D. Unpredictable - The m.e.p. of a petrol engine first increases as the fuel air ratio is increased and then decreases on further increase in fuel air ratio. The M.E.P is maximum in the zone of________________?
A. lean mixture
B. chemically correct mixture
C. rich mixture
D. unpredictable
E. none of the above - Incomplete combustion can be best judged by__________________?
A. smoky chimney exit
B. excess air in flue gases
C. measuring carbon mono-oxide in flue gases
D. measuring temperature of flue gases at exit of furnace
E. measuring oxygen in flue gases - The three “Ts” for good combustion are____________________?
A. temperature, time, and turbulance
B. total air, true fuel, and turbulance
C. thorough mixing, total air, and temperature
D. total air, time, and temperature
E. none of the above - Spontaneous combustion is a phenomenon in which____________________?
A. all the fuel burns instantaneously producing high energy release
B. fuel burns with less air
C. coal bursts into flame without any external ignition source but by itself due to gradual increase in temperature as a result of heat released by combination of oxygen with coal
D. explosion in furnace
E. none of the above - In open combustion chamber in diesel engines____________________?
A. the shape and layout of the piston crown, the inlet port, and the valve produce the turbulent effect on fuel mixture
B. fuel is injected into an auxiliary chamber that is separated from the cylinder by an orifice or throat
C. only a part of air charge is contained in an auxiliary chamber in which the fuel starts to burn with insufficient air which due to explosion tendency mixes thoroughly into main cylinder charge
D. fuel is injected at atmospheric pres¬sure
E. there are no valves. - The basic requirement of a good combustion chamber is___________________?
A. high compression ratio
B. low compression ratio
C. low volumetric efficiency
D. minimum turbulence
E. high power output and high thermal efficiency
