| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.39 |
| Score | 0% | 68% |
Which of the following is not an advantage that disc brakes have over drum brakes?
are more easily cooled |
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provide a larger contact area |
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provide more braking force |
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use less brake fluid |
Brakes utlize friction to slow vehicle tires. Drum brakes employ a cast iron drum that roates with the vehicle axle. When hydraulic pressure is applied to the brake assemblies at the wheels, internal pistons expand and push brake shoes outward into contact with the brake drum slowing the rotation of the axle. More powerful disc brakes operate by pinching a rotating disc betweeen two brake pads and allow for a larger surface area to contact the disc, provide more force, and are more easily cooled.
Modern car engines are cooled by:
air |
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air conditioner |
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ice |
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liquid |
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 statements about an inline cylinder configuration is false?
cylinders are configured in a single row |
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increases the length of the engine |
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cylinders can be completely vertical or slanted |
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works well in eight cylinder engines |
An inline cylinder configuration places the cylinders in a single row either completely vertical or slanted. Due to this arrangement, an inline cylinder configuration makes the engine longer and, although it works well in four cylinder engines, performace suffers in larger engines due to the difficulty in evenly distributing the air-fuel mixture over the length of the engine.
The stoichiometric ratio is approximately:
14.7:1 |
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1:1 |
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14.7 |
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1:14.7 |
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 is the large casing that contains the cylinders and many of the internal components of the engine?
engine block |
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chassis |
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transmission |
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manifold |
The engine (or cylinder) block is the large casing that contains the cylinders and many of the internal components of the engine.