Conocimientos generales · página 12 de 19
Preguntas de Conocimientos generales 221–240
Parte del banco de 376 preguntas de Conocimientos generales. Cada respuesta cita el Manual CDL de FMCSA o la norma federal de donde proviene.
Practicar estas en una sesión cronometradaTraducción en revisión. Se muestra el contenido actualizado en inglés. Cargo that is not properly secured in a trailer can affect vehicle handling by:
Improperly secured cargo can shift during acceleration, braking, or cornering, dramatically altering axle weight distribution. This can cause understeer, oversteer, or rollover.
49 CFR § 393.100 · Weight — Cargo Securement · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. Under the federal Interstate Highway System limits, what maximum weight generally applies to a tandem axle group?
Federal Interstate Highway System limits generally set a 34,000-pound tandem-axle limit. State rules, permits, axle spacing, and other exceptions can change what applies on a specific route.
23 U.S.C. § 127 · Weight — Tandem Axle Limits · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. A box truck is outside the vehicle categories in § 392.10. What is the federal minimum approach duty at a rail grade crossing?
Section 392.11 requires a stoppable speed and a clear-course check. Signals are not the only possible reason to stop, and the rule does not specify a universal 15-mph speed.
49 CFR § 392.11 · 392.11 slowing and clear-course requirement · verificado 2026-09-07
Traducción en revisión. Se muestra el contenido actualizado en inglés. What does a CDL Medical Examiner's Certificate (MEC) prove?
The Medical Examiner's Certificate (Form MCSA-5876) confirms that the driver has been examined by a certified medical examiner and meets the physical qualification standards in 49 CFR Part 391.
49 CFR § 391.45 · General Knowledge — Physical Qualifications · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. Which of the following results in permanent (lifetime) CDL disqualification upon a FIRST conviction?
Using a CMV to commit a felony involving manufacturing, distributing, or dispensing controlled substances results in lifetime CDL disqualification on the first offense.
49 CFR § 383.51 · General Knowledge — Disqualifying Offenses · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. What acuity does the general vision standard in 49 CFR 391.41 require?
The general standard requires at least 20/40 acuity in each eye separately, with or without corrective lenses, and at least 70 degrees of horizontal field in each eye. Part 391 also has a separate alternative vision standard for some drivers.
49 CFR § 391.41(b)(10) · General Knowledge — Vision Requirements · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. When must a CDL holder report a traffic conviction in another state to their employer?
A CDL holder must notify their employer of any traffic conviction (in any vehicle, in any state) within 30 days of the conviction, as required by 49 CFR 383.31.
49 CFR § 383.31 · General Knowledge — Driver Reporting Responsibilities · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. When driving in freezing conditions, what does “black ice” mean?
Black ice is a thin, nearly transparent layer of ice that takes on the appearance of the pavement beneath it. It is extremely slippery and difficult to see, making it especially hazardous.
FMCSA CDL Testing System — General Knowledge · General Knowledge — Weather Hazards · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. Why should a driver turn off a retarder on a wet, icy, or snow-covered road?
A retarder can cause the drive wheels to lose traction on wet, icy, or snow-covered roads. Turn it off in slippery conditions and use braking inputs appropriate to the available traction.
FMCSA CDL Testing System — General Knowledge · General Knowledge — Retarders · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. Which statement about retarder use on a slippery surface is false?
Retarders should be turned OFF on wet, icy, or snowy roads. Retarder braking force on the drive wheels can cause wheel lockup and jackknifing on slippery surfaces.
FMCSA CDL Testing System — General Knowledge · General Knowledge — Retarder Cautions · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. What is the primary danger of driving in the 'No-Zone' of a large truck?
The No-Zone areas (directly in front, behind, and on the sides of a CMV) are large blind spots where the truck driver has very limited or no visibility of surrounding vehicles.
FMCSA CDL Testing System — General Knowledge · General Knowledge — No-Zones · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. What is 'brake fade' and what causes it?
Brake fade occurs when brakes are applied repeatedly or for extended periods (such as on a long downgrade), causing drums and linings to overheat. Reduced friction between hot metal surfaces dramatically reduces braking effectiveness.
FMCSA CDL Testing System — General Knowledge · General Knowledge — Brake Fade · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. Which approach checks both resistance to separation and correct fifth-wheel engagement before a trip?
The gentle pull and the secured visual inspection answer different questions. Inspect the jaws, plates, and locking mechanism as well as testing resistance; connected hoses do not prove a locked fifth wheel.
Oregon DMV Commercial Driver Manual · 6.2.4 Air-lines; 6.2.5 Hose Couplers; 6.4.1 Coupling; 6.4.2 Uncoupling · verificado 2026-09-07
Traducción en revisión. Se muestra el contenido actualizado en inglés. During controlled braking, what should a driver do if the wheels lock or a larger steering correction is needed?
Controlled braking uses firm braking without wheel lock. If the wheels lock or a larger steering correction is needed, release the brakes and reapply them as soon as possible after control returns.
FMCSA CDL Testing System — General Knowledge · General Knowledge — Braking Techniques · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. You are driving in heavy traffic and the vehicle ahead suddenly stops. What is the safest action?
In a sudden stop situation, apply controlled braking (maximum without locking wheels) while scanning mirrors for an escape path if stopping in time is not possible. Swerving without a mirror check creates a new hazard.
FMCSA CDL Testing System — General Knowledge · General Knowledge — Crash Avoidance · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. What is the effect of doubling your speed on your vehicle's braking distance?
Braking distance is proportional to the square of your speed. If you double your speed, your braking distance increases by a factor of four (quadruples). This is why speed control is critical for CMV safety.
FMCSA CDL Testing System — General Knowledge · General Knowledge — Speed and Braking · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. What is the minimum number of tie-downs required for cargo that is 10 feet long?
Under 49 CFR 393.102, cargo must have at least one tie-down per 10 feet of cargo length (or fraction thereof), with a minimum of two tie-downs for any load. A 10-foot load requires at least 2 tie-downs.
49 CFR § 393.102 · General Knowledge — Cargo Securement · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. Which type of fire extinguisher is recommended for use on electrical fires in a CMV?
Do not use a water-based extinguisher on an energized electrical fire. A CO2 or non-water dry-chemical extinguisher is the suitable type listed for that hazard.
FMCSA CDL Testing System — General Knowledge · General Knowledge — Fire Extinguisher Types · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. What does the FMCSA manual say about air drag in modern trucks?
The FMCSA manual notes that modern trucks use streamlined shapes for fuel economy and have less air drag. It does not establish a universal percentage or speed law for fuel use.
FMCSA CDL Testing System — General Knowledge · General Knowledge — Fuel Economy · verificado 2026-06-30
Traducción en revisión. Se muestra el contenido actualizado en inglés. What action should you take if your steering suddenly becomes very difficult (power steering failure)?
If power steering fails, the vehicle can still be steered but it will require significantly more effort. Reduce speed gradually, keep both hands on the wheel, and safely exit the road. Do not continue driving with a failed power steering system.
FMCSA CDL Testing System — General Knowledge · General Knowledge — Steering Failure · verificado 2026-06-30
