Hydroplaning:
Answer: B
Is more likely if tire pressure is low.
Hydroplaning can happen at speeds as low as 30 mph, and it does not take much water to cause it. It is more likely to occur if the tire pressure is low or the tread is worn, which means the grooves are not deep enough to carry the water away and ensure the tire's contact with the road.
All choices
- AOnly occurs when there is a lot of water.
- BIs more likely if tire pressure is low.
- CCannot occur when driving through a puddle.
Why the other answers are wrong
A. Only occurs when there is a lot of water.
Hydroplaning can occur with small amounts of water, not only when there is a lot of water.
C. Cannot occur when driving through a puddle.
Hydroplaning can occur when driving through puddles if conditions allow.
CDL General Knowledge Test Info
Questions on Exam
50
Passing Score
80%
Time Limit
Typically 60 minutes; varies by testing location
The General Knowledge test content is federally standardized, so this question applies in every state. Age limits, fees, and testing procedures do vary — check your state's CDL requirements.
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