In a typical medium speed 4-stroke cycle diesel engines Exhaust valve opens at bottom dead center and closes at top dead center May open and close anywhere Exhaust valve opens just after bottom dead center and closes just before top dead center Exhaust valve opens at 35° before bottom dead center and closes at 20° after top dead center TRUE ANSWER : ? YOUR ANSWER : ?
The air requirement of a petrol engine during starting compared to theoretical air required for complete combustion is Less Same May be more or less depending on engine capacity More TRUE ANSWER : ? YOUR ANSWER : ?
The octane number of petrol, generally available, is 60 to 80 40 to 60 20 to 40 80 to 100 TRUE ANSWER : ? YOUR ANSWER : ?
The thermal efficiency of diesel engines on weak mixtures is Dependent on other factors Lower Unaffected Higher TRUE ANSWER : ? YOUR ANSWER : ?
If the compression ratio of an engine working on Otto cycle is increased from 5 to 7, the percentage increase in efficiency will be 0.08 0.14 0.04 0.02 TRUE ANSWER : ? YOUR ANSWER : ?
The increase of efficiency of a compression ignition engine, as the load decreases, is due to Hit and miss governing Higher maximum temperature Qualitative governing Quantitative governing TRUE ANSWER : ? YOUR ANSWER : ?
The volumetric efficiency of a well designed engine may be 30 to 40% 60 to 70% 40 to 60% 75 to 90% TRUE ANSWER : ? YOUR ANSWER : ?
The thermal efficiency of a diesel cycle having fixed compression ratio, with increase in cut-off ratio will May increase or decrease depending on other factors Decrease Be independent Increase TRUE ANSWER : ? YOUR ANSWER : ?
If V₁ is the jet velocity and V₀ is the vehicle velocity, then propulsive efficiency of a turbojet engine is 2V₀ / (V₀ + V₁) V₁ / (V₀ + V₁) V₀ / (V₀ + V₁) 2V₁ / (V₀ + V₁) TRUE ANSWER : ? YOUR ANSWER : ?
The accumulation of carbon in a cylinder results in increase of Clearance volume Effective compression ratio Volumetric efficiency Ignition time TRUE ANSWER : ? YOUR ANSWER : ?