Take Delaware CDL General Knowledge Practice Questions - Delaware Commercial Driver License General Knowledge Test Exam

QUESTION 1 / 25

When performing a pre-trip inspection, the driver should ensure that the steering wheel free play (lash) does not exceed what limit?

Choose one answer below.

A5 degrees in either direction✓B10 degrees in either direction (approximately 2 inches on a 20-inch wheel)✓C15 degrees in either direction✓D20 degrees in either direction✓

QUESTION 2 / 25

During the cab check portion of a pre-trip inspection, you should test the parking brake by:

Choose one answer below.

ADriving forward slowly and applying the parking brake✓BPutting the vehicle in gear with the parking brake set and gently pressing the accelerator to see if the vehicle holds✓CVisually checking that the parking brake handle is in the correct position✓DChecking the parking brake cable under the vehicle✓

QUESTION 3 / 25

Which emergency equipment is required to be on a commercial motor vehicle?

Choose one answer below.

AFire extinguisher, spare fuses, and three red reflective triangles✓BFirst aid kit, fire extinguisher, and flares only✓CFire extinguisher and road flares only✓DSpare tire, jack, and reflective vest✓

QUESTION 4 / 25

A post-trip inspection report is important because:

Choose one answer below.

AIt is only required for vehicles carrying hazardous materials✓BIt alerts the carrier to vehicle defects that may need repair before the vehicle is driven again✓CIt replaces the need for the next driver to do a pre-trip inspection✓DIt is optional but recommended by the FMCSA✓

QUESTION 5 / 25

During a pre-trip inspection, the driver notices a coolant leak near the water pump. What should the driver do?

Choose one answer below.

ANote it on the report and drive carefully to the next service stop✓BAdd more coolant and continue the trip✓CDo not drive the vehicle until the leak is repaired✓DDrive only short distances and monitor the temperature gauge✓

QUESTION 6 / 25

Which of the following is an out-of-service condition that would prevent a vehicle from being driven?

Choose one answer below.

AA small crack in the windshield that does not obstruct the driver's view✓BA missing mud flap on a rear wheel✓CBrake lining thickness below the minimum allowed by regulations✓DA broken antenna on the CB radio✓

QUESTION 7 / 25

During the pre-trip inspection, which of the following should a driver check regarding the exhaust system?

Choose one answer below.

AOnly that the muffler is present✓BThat the exhaust system is secure, not leaking, and not in contact with fuel lines, wiring, or air lines✓COnly that exhaust fumes are not entering the cab✓DThat the catalytic converter is functioning properly by checking emissions color✓

QUESTION 8 / 25

What is the minimum tread depth required for steer axle tires on a commercial motor vehicle?

Choose one answer below.

A2/32 of an inch✓B4/32 of an inch✓C6/32 of an inch✓D1/32 of an inch✓

QUESTION 9 / 25

What is the minimum tread depth required for tires on drive and trailer axle positions?

Choose one answer below.

A4/32 of an inch✓B2/32 of an inch✓C6/32 of an inch✓D1/32 of an inch✓

QUESTION 10 / 25

When inspecting slack adjusters on an S-cam brake system, the pushrod stroke at the brake chamber should not exceed what general limit?

Choose one answer below.

A1/2 inch✓B1 inch✓CThe adjustment limit varies by chamber size, but generally should not exceed about 2 inches✓D4 inches✓

QUESTION 11 / 25

During a tire inspection, you notice a bulge on the sidewall of one of the steer tires. What should you do?

Choose one answer below.

AContinue driving but avoid high speeds✓BHave the tire replaced before driving the vehicle✓CRotate the tire to a non-steer position✓DReduce air pressure to alleviate the bulge✓

QUESTION 12 / 25

What is the purpose of the brake drum inspection during a pre-trip?

Choose one answer below.

ATo check if the drums are painted correctly✓BTo look for cracks, broken welds, or holes and to check that the drum is not contaminated with oil or grease✓CTo measure the exact diameter of the drum with calipers✓DTo verify the brand of the brake drum✓

QUESTION 13 / 25

When should you place your reflective triangles after stopping on the road due to a breakdown?

Choose one answer below.

AWithin 30 minutes of stopping✓BWithin 10 minutes of stopping✓COnly if it is dark outside✓DOnly on highways with speed limits over 55 mph✓

QUESTION 14 / 25

What is the proper technique for shifting gears in a commercial motor vehicle with a manual transmission (double clutching)?

Choose one answer below.

APress the clutch, shift to neutral, release the clutch, press the clutch again, shift to the next gear, release the clutch✓BHold the clutch down while moving through each gear✓CShift without using the clutch at any time✓DPress the clutch once and move the shifter directly to the next gear✓

QUESTION 15 / 25

What is "off-tracking" when driving a commercial vehicle through a turn?

Choose one answer below.

AWhen the vehicle drifts out of its lane on a straight road✓BWhen the rear wheels follow a shorter path (closer to the inside of the curve) than the front wheels✓CWhen the trailer fishtails on slippery roads✓DWhen the steering wheel locks during a turn✓

QUESTION 16 / 25

When turning right with a large commercial vehicle, the correct technique is to:

Choose one answer below.

ATurn tightly to stay as close to the curb as possible✓BSwing wide to the left before turning right to give the rear wheels room to clear the corner✓CKeep the front wheels close to the right curb and allow the trailer to track over the curb✓DStop in the intersection and wait for all traffic to clear✓

QUESTION 17 / 25

What does countersteering mean?

Choose one answer below.

ATurning the steering wheel in the direction opposite to the way you want to go✓BTurning the steering wheel back toward straight ahead after completing a turn to prevent oversteering✓CSteering with one hand while braking with the other✓DSteering the vehicle in reverse✓

QUESTION 18 / 25

When driving a commercial vehicle, the driver should be aware that the vehicle's total stopping distance at highway speed is significantly greater than a passenger car. At 55 mph, the total stopping distance for a fully loaded tractor-trailer on dry pavement is approximately:

Choose one answer below.

A100 feet✓B200 feet✓C300 to 400 feet✓D600 feet or more✓

QUESTION 19 / 25

What is the proper RPM range for shifting gears in most commercial diesel engines?

Choose one answer below.

A500 to 1,000 RPM✓B1,000 to 1,500 RPM (the "sweet spot" for most diesel engines)✓C2,500 to 3,500 RPM✓D4,000 to 5,000 RPM✓

QUESTION 20 / 25

During an alley dock backing maneuver, the driver should:

Choose one answer below.

ABack as quickly as possible to reduce the number of steering corrections needed✓BPosition the vehicle at an angle to the dock opening, then use pull-ups as needed to straighten the trailer into the dock✓CAlways back straight into the dock without angling the vehicle✓DOnly use the driver-side mirror during the maneuver✓

QUESTION 21 / 25

When performing a parallel parking maneuver with a commercial vehicle, what is the key challenge?

Choose one answer below.

AFinding a parking space large enough, typically 10 to 15 feet longer than the vehicle✓BThe vehicle's off-tracking, which requires significantly more space than a passenger car and careful mirror monitoring✓CParallel parking is not a required CDL skill✓DThe vehicle's speed must remain above 5 mph during the maneuver✓

QUESTION 22 / 25

If a trailer begins to drift off course while backing in a straight line, the driver should:

Choose one answer below.

AImmediately stop and start over✓BMake a small steering correction toward the drift early, before the trailer gets far off course✓CSpeed up to straighten the trailer✓DMake a large steering correction in the opposite direction of the drift✓

QUESTION 23 / 25

When backing a trailer around a corner (offset backing), the driver should:

Choose one answer below.

ATurn the steering wheel sharply and back quickly✓BSteer toward the direction they want the trailer to go, check both mirrors frequently, and use pull-ups if needed✓COnly use the driver-side mirror✓DKeep the steering wheel straight and let the trailer follow naturally✓

QUESTION 24 / 25

On a long downgrade, the proper technique for controlling speed is:

Choose one answer below.

AApply the brakes continuously with steady pressure to maintain a safe speed✓BUse the "snub braking" technique: apply brakes firmly to slow 5 mph below target speed, release brakes, and repeat✓CCoast in neutral to save fuel and let the vehicle speed up naturally✓DRide the brakes lightly throughout the entire downgrade✓

QUESTION 25 / 25

What is the difference between controlled braking and stab braking?

Choose one answer below.

AThey are the same technique with different names✓BControlled braking applies steady pressure just short of wheel lockup; stab braking applies full brake pressure, releases when wheels lock, then reapplies✓CControlled braking is for dry roads only; stab braking is for wet roads only✓DStab braking provides shorter stopping distances than controlled braking in all situations✓