A. increase the knocking tendency
B. decrease the knocking tendency
C. not affect the knocking tendency
D. increase or decrease knocking tendency depending on strength and time of spark
E. unpredictable
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 - 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 - 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
E. engine cooling is stopped - The thermal efficiency of a petrol engine of two stroke with crank case scavenging as compared to four stroke petrol engine with same comperssion ratio will be_____________________?
A. higher
B. lower
C. same
D. depends on size of engine
E. unpredictable. - The m.e.p. of a diesel cycle having fixed compression ratio with increase in cut-off will_________________?
A. increase
B. decreae
C. be unaffected
D. depend on other factors
E. unpredictable - In petrol engine, increase of cooling water temperature will_________________?
A. increase the knocking tendency
B. decrease the knocking tendecny
C. not affect the knocking tendency
D. increase or decrease knocking tendency depedning on strength and time of spark
E. unpredictable - The specific fuel consumption of a petrol engine compared to diesel engine of same H.P. is_______________?
A. same
B. more
C. less
D. less or more depending on operating conditions
E. unpredictable - The thermal efficiency of a semi-diesel cycle having fixed compression ratio and fixed quantity of heat, with increase in pressure ratio will_______________?
A. increase
B. decrease
C. remain unaffected
D. increase/decrease depending upon engine capacity
E. first increase and then decrease - 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
E. will work at all ratios
