COMBINATION PRACTICE TEST - IN CDL
11.
If you are driving a 30 foot vehicle at 35 mph, you should leave at least _______ between your vehicle and the vehicle in front of you.
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3 seconds
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4 seconds
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1 seconds
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2 seconds
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12.
The wheels of a large combination vehicle are more likely to lock up when:
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the vehicle is heavily loaded.
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you are traveling in very hot weather.
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the vehicle is lightly loaded.
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the trailer has new tires.
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13.
Hanging meat in a refrigerated truck can be:
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a very unstable load with a high center of gravity.
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a very stable load if properly distributed.
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a very stable load with a low center of gravity.
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a very unstable load with a low center of gravity.
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14.
After a tire has been changed, the driver should stop a short while later to:
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check the tightness of the nuts.
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check tread separation.
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decrease tire pressure.
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deflate the tire to 10 psi.
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15.
When you turn suddenly while pulling doubles, which trailer is most likely to turn over?
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The front trailer is twice as likely to turn over as the tractor.
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The rear trailer is twice as likely to turn over as the tractor.
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All trailers are equally likely to turn over.
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None of the above.
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16.
If you unlock the pintle hook with the dolly still under the rear trailer:
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the dolly tow bar may fly up.
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the brakes could be damaged by the combined forces of the springs and the air pressure.
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your vehicle might roll away.
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steam and boiling water can spray under pressure.
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17.
When inspecting the coupling, make sure the fifth-wheel jaws have closed around the:
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the electrical cord.
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shank of the kingpin.
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the brake camshaft.
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head of the kingpin.
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18.
As you approach off ramps and on ramps, remember:
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to always brake and turn at the same time.
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that downgrades make it easier to reduce speed.
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that the posted speed limit may not be safe for larger vehicles.
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to maintain your highway speed.
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19.
In combination vehicles with air brakes, the trailer air supply control should pop out when the air pressure falls within the range of:
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10 to 20 psi
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100 to 120 psi
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20 to 45 psi
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50 to 75 psi
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20.
If ABS is not working:
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you should use the parking brake.
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you will not have any brakes.
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you will still have brakes.
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you should use the emergency brake.
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