Free, full Kentucky CDL general knowledge test practice right here in your browser — real exam format (50 questions, 80% to pass), diagnostic and adaptive modes, spaced-repetition review, and a readiness dashboard. No signup, no paywall — your progress is saved automatically on this device.
If your vehicle is involved in an accident with injuries, you should NOT:
A. Move seriously injured persons unless there is a fire danger — Do not move seriously injured persons unless there is immediate danger such as fire, as movement could worsen injuries.
Which type of fire extinguisher is recommended for use on electrical fires in a CMV?
D. CO2 or dry chemical (non-water type) — Water-based extinguishers conduct electricity and should never be used on electrical fires. CO2 (carbon dioxide) or dry chemical (BC or ABC) extinguishers are safe for electrical fires. Most CMVs carry ABC dry chemical.
Under FMCSA Hours of Service rules, a property-carrying driver may drive a maximum of how many hours after 10 consecutive off-duty hours?
A. 11 hours — Property-carrying drivers may drive a maximum of 11 hours after taking 10 or more consecutive off-duty hours. This is the 11-Hour Driving Limit under FMCSA regulations.
The air compressor is connected to the engine through:
D. Gears or a V-belt — The air compressor is driven by the engine through gears or a V-belt and pumps air into the air storage tanks.
When using a fire extinguisher on a vehicle fire, you should aim:
B. At the base of the fire, staying as far back as the extinguisher allows — Aiming at the base of the fire and staying back puts out the source while keeping you clear of heat, smoke, and flare-ups.
The safety chains on a converter dolly are designed to:
B. Prevent the dolly's drawbar from dropping to the ground if it disconnects from the trailer — Safety chains on a converter dolly are there to keep the dolly's drawbar (tongue) from dragging on the road if it becomes disconnected from the trailer's pintle hook.
Hazmat Class 3 covers:
C. Flammable liquids — Hazmat Class 3 covers flammable liquids — substances that ignite easily at or below 140°F (60°C). Examples include gasoline, diesel fuel, ethanol, and paint thinner. Class 3 materials require a red FLAMMABLE placard and specific handling and parking rules.
What is the primary purpose of retarders (engine brake, jake brake) on a CMV?
C. To slow the vehicle using engine compression, reducing brake wear on long grades — Retarders (engine brakes, exhaust brakes, hydraulic retarders) slow the vehicle using engine resistance rather than friction brakes. They are most useful on long downgrades to prevent brake fade. Turn them off on slippery roads.
What are the three emergency equipment items required on commercial vehicles?
A. Fire extinguisher, spare fuses, warning triangles — Federal law requires all commercial motor vehicles to carry a fire extinguisher of the correct type and rating, a set of three reflective warning triangles, and spare electrical fuses — missing any item is an out-of-service violation.
During inspection, leaf springs should be checked for:
C. Broken or missing leaves, shifts, or cracks — Inspect leaf springs for cracked, broken, or missing leaves. Shifted spring assemblies can affect vehicle handling.
The Kentucky CDL general knowledge test has 50 questions, and you need 80% to pass — at least 40 correct answers. The practice tests on this page use the same format. The 80% passing score is a federal FMCSA standard used by every state.
80%. You can miss at most 10 of the 50 questions. The readiness dashboard on this page tracks whether you're consistently scoring above that bar.
Yes. Every practice test on this page and everything in the DMVPrep iPhone app is free — no ads, no paywall, no account.
Federal motor carrier safety regulations (FMCSA) — the same rules every state's CDL exam is drawn from. Every question in the DMVPrep app cites the regulation or handbook section it comes from.
Yes — the DMVPrep app includes all 3,745+ questions in Spanish, and the whole app works in Spanish.