| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.02 |
| Score | 0% | 60% |
What is the name of the proper ratio of air to fuel necessary so that an engine burns all fuel with no excess air?
stoichiometric ratio |
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ignition ratio |
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residual ratio |
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combustion ratio |
The stoichiometric ratio defines the proper ratio of air to fuel necessary so that an engine burns all fuel with no excess air. For gasoline fuel, the stoichiometric ratio is about 14.7:1 or for every one gram of fuel, 14.7 grams of air are required. Too much air results in a lean air-fuel mixture that burns more slowly and hotter while too much fuel results in a rich mixture that burns quicker and cooler.
What function does a two-stroke cycle engine perform on the second stroke?
combustion and exhaust |
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fuel intake and exhaust |
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fuel intake and compression |
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compression and combustion |
The two strokes of a two-stroke cycle engine are fuel intake and compression then combustion and exhaust.
Just before the piston reaches top dead center, the spark plug fires and ignites the compressed air-fuel mixture. This describes which engine stroke?
intake |
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power |
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exhaust |
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compression |
During the power stroke, just before the piston reaches top dead center, the spark plug fires and ignites the compressed air-fuel mixture. The resulting expansion due to combustion pushes the piston back down the cylinder toward bottom dead center.
What links each piston to the engine's crankshaft?
halfshaft |
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connecting rod |
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cylinder arm |
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piston ring |
A connecting rod employs a wrist pin to link each piston to the engine's crankshaft.
Power brakes multiply the force a driver applies to the brake pedal using a __________ connected to the engine intake manifold.
vacuum booster |
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cylinder |
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speed sensor |
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brake line |
Power brakes multiply the force a driver applies to the brake pedal using a vacuum booster connected to the engine intake manifold. This provides for much higher hydraulic pressure in the braking system than could be generated by the driver alone. Antilock brakes (ABS) use speed sensors and adjust the brake pressure at each wheel to prevent skidding and allow the driver more steering control in slippery conditions.