Free CDL Quiz

What is the kingpin?

a.A pin that locks the trailer doors
b.A pin on the underside of the trailer front that locks into the fifth wheel
c.A pin that holds the landing gear in place
d.A pin used to adjust the fifth wheel position

Explanation

The kingpin is a large steel pin on the underside of the front of the trailer. It fits into and locks within the fifth wheel on the tractor. It is the main coupling point between the tractor and trailer.

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About the CDL Exam

The CDL (Commercial Driver License) exam tests your knowledge of commercial driving rules, safety procedures, and vehicle operation. You must score 80% or higher to pass the written knowledge test. The exam covers general knowledge, air brakes, combination vehicles, and various endorsements.

This question is from the CDL Combination Test #1 section. Practice with more questions from this category to build confidence before taking the official DMV test.

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