CSLB General Building (B) Trade Practice Test

Preguntas de práctica de ejemplo

Algunas preguntas reales de este banco gratuito, con explicaciones completas. Usa la herramienta de arriba para el banco completo.

1. 1. Engine Repair (A1)

   A cylinder head is warped beyond specification. Which service is normally required to restore a flat sealing surface?

   • a.Replacing the head bolts only
   • b.Installing a thicker head gasket
   • c.Resurfacing (machining) the head
   • d.Retorquing the head while hot

   Respuesta: c

   Explicación: A warped head must be resurfaced by machining to bring the deck within flatness specification. A thicker gasket will not correct an uneven surface, and simply retorquing does not remove the warp. Excessive material removal, however, can raise compression and change valve timing on some engines.

2. 2. Engine Repair (A1)

   The main function of engine oil, besides lubrication, includes all of the following EXCEPT:

   • a.Cooling internal components
   • b.Generating spark for combustion
   • c.Cleaning and suspending contaminants
   • d.Sealing between rings and cylinder walls

   Respuesta: b

   Explicación: Engine oil lubricates, cools, cleans, and helps seal the rings, but it plays no role in generating spark. Spark is produced by the ignition system. Detergent and dispersant additives keep contaminants suspended until the filter or an oil change removes them.

3. 3. Transmission & Drivetrain (A2/A3)

   Technician A says most dipstick-equipped automatics are checked with the engine running at operating temperature. Technician B says fluid level is unaffected by temperature. Who is correct?

   • a.Both A and B
   • b.Technician A only
   • c.Technician B only
   • d.Neither A nor B

   Respuesta: b

   Explicación: Dipstick-equipped automatics are checked hot with the engine running and the selector cycled, and fluid expands with temperature so the reading depends on it. Technician B is wrong. Many modern units use a sealed fill within a specified fluid-temperature window.

4. 4. Suspension & Steering (A4)

   Cupping or scalloping tire wear is most commonly associated with:

   • a.Worn suspension dampers or unbalanced wheels
   • b.Excessive toe-in
   • c.A slipping clutch
   • d.Over-torqued lug nuts

   Respuesta: a

   Explicación: Cupping, a series of dips around the tread, results from the tire bouncing due to worn shocks/struts or from imbalance. It usually comes with a noise that changes with speed. Correcting the damper or balance issue and rotating tires helps.

5. 5. Brakes (A5)

   Technician A says a pulsating brake pedal is usually caused by air in the hydraulic lines. Technician B says it is usually caused by rotor thickness variation or excessive lateral runout. Who is correct?

   • a.Technician A only
   • b.Technician B only
   • c.Both A and B
   • d.Neither A nor B

   Respuesta: b

   Explicación: Thickness variation or warp causes the pads to move in and out as the disc turns, producing a pulsation felt in the pedal, while air produces a soft pedal instead. Technician B is correct. Measuring runout and thickness variation confirms it.

6. 6. Brakes (A5)

   A proportioning valve in the brake system is designed to:

   • a.Reduce pressure to the rear brakes to prevent early lockup
   • b.Increase pressure to the front only
   • c.Store extra brake fluid
   • d.Operate the parking brake

   Respuesta: a

   Explicación: Because weight shifts forward during braking, the proportioning valve limits rear brake pressure to keep the rear wheels from locking prematurely. This maintains stability during hard stops. Many vehicles now handle this function electronically through ABS/EBD.

7. 7. Electrical (A6)

   Technician A says a fuse that blows again immediately after replacement indicates a short to ground or an overload. Technician B says repeatedly replacing the fuse will fix the circuit. Who is correct?

   • a.Technician A only
   • b.Both A and B
   • c.Technician B only
   • d.Neither A nor B

   Respuesta: a

   Explicación: A fuse that blows again immediately is protecting the circuit from a short to ground or an overload drawing excess current. Technician B is wrong because the underlying fault, not the fuse, must be repaired. Inspect the wiring for chafing and test the component.

8. 8. Heating & A/C (A7)

   The expansion valve or orifice tube controls:

   • a.Compressor speed
   • b.Blower motor voltage
   • c.The flow of refrigerant into the evaporator, causing a pressure drop
   • d.Cabin air recirculation

   Respuesta: c

   Explicación: The metering device drops the refrigerant pressure and controls flow into the evaporator, allowing it to boil and absorb heat. A restricted orifice or stuck valve causes poor cooling and abnormal pressures. It separates the high side from the low side of the system.

9. 9. Engine Performance (A8)

   Technician A says a rich air-fuel mixture can raise tailpipe CO and HC. Technician B says the oxygen sensor helps the PCM keep the mixture near stoichiometric. Who is correct?

   • a.Technician A only
   • b.Technician B only
   • c.Both A and B
   • d.Neither A nor B

   Respuesta: c

   Explicación: A rich mixture leaves excess fuel that raises carbon monoxide and hydrocarbons, and the oxygen sensor feedback lets the PCM hold the mixture near the ideal ratio. Both technicians are correct. A lazy sensor degrades fuel control and emissions.

10. 10. Engine Performance (A8)

    The exhaust gas recirculation (EGR) system reduces which emission by lowering combustion temperature?

    • a.Carbon monoxide (CO)
    • b.Oxides of nitrogen (NOx)
    • c.Hydrocarbons (HC)
    • d.Carbon dioxide (CO2)

    Respuesta: b

    Explicación: EGR routes inert exhaust gas back into the intake to lower peak combustion temperature, reducing the formation of NOx. A clogged EGR passage can cause knock and high NOx, while a stuck-open valve causes rough idle. Its operation is monitored by OBD-II.