CDL Tanker Endorsement

What is 'liquid surge' in a tank vehicle?

1. AThe foaming of liquid caused by rough road surfaces
2. BThe leakage of liquid past a faulty valve
3. CThe wave action of liquid that moves back and forth when the vehicle changes speed正确
4. DThe buildup of vapor pressure inside a sealed tank

为什么: Liquid surge is the movement of liquid in partially filled tanks. When the driver brakes, the liquid surges forward and can push the truck ahead, then rock it backward. This wave action can strongly affect vehicle handling and control.

What is the main reason tank vehicles roll over more easily than other trucks?

1. ATheir extra-wide tires
2. BTheir high center of gravity combined with liquid surge正确
3. CTheir low ground clearance
4. DTheir light overall weight

为什么: Tank vehicles carry weight high off the ground and the liquid inside can surge and shift. This high center of gravity plus surging cargo makes them easy to tip in curves and sudden maneuvers. Driving slowly and smoothly is the best defense against rollover.