SC CDL DOUBLES TRIPLES TEST - PRACTICE TEST

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Safely pulling double and triple trailers requires knowledge and skill. If you want to pull double or triple trailers, you must add the Doubles/Triples (T) endorsement to your Class A CDL. The South Carolina doubles triples test consists of 20 questions. To pass, you must correctly answer at least 16 questions (80%). The SC CDL doubles triples test covers the following sections of the South Carolina CDL Manual: Driving Safely, Air Brakes (if you plan to operate vehicles equipped with air brakes), Combination Vehicles, Doubles and Triples. Take this SC CDL practice test now to prepare for the actual test!
1. Which of the following will off-track the most?
The rear wheels of the tractor.
The rear wheels of the last trailer.
The front wheels of the tractor.
The front wheels of the last trailer.
2. To warn drivers behind you when you see you'll need to slow down, you should:
turn off your lights.
sound your horn.
flash the brake lights.
use your headlights.
3. If your vehicle thumps or vibrates heavily, it may be a sign that:
the engine belt is loose.
you need to shift up.
one of the tires has gone flat.
the brakes have failed.
4. When the wheels of a trailer lock up:
the trailer will tend to swing around.
the vehicle will gradually come to a complete stop.
ABS will increase stopping power.
All of the above.
5. If your brakes fail on a steep mountain downgrade, you should:
use an escape ramp if it is available.
leave the road immediately.
change lanes after making sure there is enough room.
go right if the shoulder is clear.
6. When driving a double or triple, you should:
increase your following distance.
drive with emergency flashers on.
decrease your following distance.
drive in the left lane whenever possible.
7. Which of these describes the proper braking technique when driving on a long and steep downgrade?
Release the brakes until your speed is 5 mph above your safe speed, then apply the brakes. When your speed has decreased to your safe speed, repeat the previous steps.
Apply the brakes. When your speed has been reduced to 5 mph below your safe speed, release the brakes. When your speed has increased to your safe speed, repeat the previous steps.
Apply the brakes until your speed has been reduced to 5 mph, then release the brakes. When your speed has increased to your safe speed, repeat the previous steps.
All of the above.
8. To start moving without rolling back, you should:
apply the trailer brake hand valve.
partly engage the clutch before you take your right foot off the brake.
put on the parking brake whenever necessary.
All of the above.
9. Skids caused by acceleration can usually be stopped by:
coming to a complete stop.
speeding up.
taking the foot off the accelerator.
applying the brakes firmly.
10. Cargo should be properly covered:
to protect the weather from the cargo.
to block your view or someone else’s.
to protect people from spilled cargo.
All of the above.
 
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SC Doubles Triples Test

Number of questions: 20
Correct answers to pass:16
Passing score:80%
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