| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.17 |
| Score | 0% | 63% |
The right front wheel of your front-wheel drive car drops into a pothole and the left front wheel doesn't lose contact with the road. Which of the following is true?
your car has a rigid axle rear suspension |
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your car has a rigid axle front suspension |
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your car has an independent front suspension |
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your car has an independent rear suspension |
An independent suspension allows the wheels on either side of an axle to move independently from each other. The fact that the left front wheel didn't move up in response to the right front wheel moving down is evidence of this.
__________ results from oil buildup in the combustion chamber.
combustion |
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detonation |
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preignition |
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engine knock |
Preignition results from the buildup of fuel deposits and/or oil in the combustion chamber. These deposits increase chamber pressure and reduce heat tranfer to the coolant. The trapped heat then raises the temperature of the air-fuel mix to the point that it combusts before ignition.
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.
Modern car engines are cooled by:
ice |
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air conditioner |
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liquid |
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air |
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.
Which of the following is not a function of antifreeze?
aids heat transfer |
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keeps water from freezing at low temperatures |
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lubricates the cooling system |
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raises the boiling point of water |
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.