| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.11 |
| Score | 0% | 62% |
What links each piston to the engine's crankshaft?
piston ring |
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cylinder arm |
|
halfshaft |
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connecting rod |
A connecting rod employs a wrist pin to link each piston to the engine's crankshaft.
Just before the piston reaches top dead center, the spark plug fires and ignites the compressed air-fuel mixture. This describes which engine stroke?
power |
|
exhaust |
|
intake |
|
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.
Which of the following is not a function of antifreeze?
aids heat transfer |
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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 |
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 engine stroke starts with the piston at top dead center?
compression stroke |
|
power stroke |
|
exhaust stroke |
|
intake 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.
What is the pimary advantage of using power brakes on a vehicle?
allows the use of antilock brakes |
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provides higher hydraulic pressure in the braking system |
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utilizes battery power to assist in braking |
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requires less brake fluid to operate the braking system |
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.