| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.23 |
| Score | 0% | 65% |
Which of the following is not a function of antifreeze?
lubricates the cooling system |
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raises the boiling point of water |
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keeps water from freezing at low temperatures |
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aids heat transfer |
Modern car engines are cooled by liquid which circulates through the engine block and cylinder heads absorbing excess heat. This liquid is made up of half water and half antifreeze (commonly, ethylene glycol) which both keeps the water from freezing at low temperatures and raises its boiling point making heat transfer more efficient.
Ignition timing is measured in number of degrees:
before bottom dead center |
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after bottom dead center |
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after top dead center |
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before top dead center |
Ignition timing defines the point in time at the end of the compression stroke that the spark plug fires. Measured in number of degrees before top dead center (BTDC), the exact point that the spark plugs initiate combustion varies depending on the speed of the engine. The timing is advanced (the spark plugs fire a few more degrees BTDC) when the engine is running faster and retarded when it's running slower.
In a four-stroke piston cycle, one piston is always:
compressing the air-fuel mixture |
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all of these are correct |
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exhausting gases |
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delivering power |
In a four-stroke cycle engine there is always one piston delivering power, one exhausting gases, one drawing in the air-fuel mixture, and one compressing that mixture.
The intake ports on the cylinder heads is fed outside air via the:
intake pressure regulator |
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intake manifold |
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intake air pump |
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intake control module |
The intake manifold distributes outside air to the intake ports on the cylinder heads. The intake air filter removes any airborne contaminants before the air enters the engine.
Which engine stroke starts with the piston at top dead center?
exhaust stroke |
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power stroke |
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intake stroke |
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compression stroke |
The four-stroke piston cycle of internal combustion engines starts with the piston at top of the cylinder head (top dead center or TDC) during the intake stroke. The piston moves downward in the cylinder creating a vacuum that pulls an air-fuel mix into the combustion chamber through the now open intake valve.