Automotive
1. What is a carburetor's main function?
(A) To control the timing of the pistons
(B) To provide the right mix of fuel and air to the engine
(C) To keep the engine turning between power impulses from combustion in each cylinder
(D) To control voltage to the ignition coil
1. (B) A carburetor's main function is to provide the right mix of fuel and air to the engine.
2. What are the four strokes in the combustion cycle, in order?
(A) Intake, ignition, compression, exhaust
(B) Intake, compression, combustion, exhaust
(C) Compression, combustion, intake, exhaust
D) Ignition, intake, compression, exhaust
2. (B) The four strokes in the combustion cycle, in order, are intake, compression, combustion, and exhaust.
The _ change the up-and-down motion of the pistons into rotary motion,
(A) rocker arms and rods
(B) camshaft and valve heads
(C) connecting rod and crankshaft
(D) flywheel and crankshaft
3. (C) The connecting rod and crankshaft change the up-and-down motion of the pistons into rotary motion.
4. An automobile's radiator is involved in
(A) lubricating the engine.
(B) atomizing fuel flow in the correct ratio.
(C) pumping fuel from the tank to the engine.
(D)cooling the engine.
4. (D) An automobile's radiator is involved in cooling the engine. The oil pump is involved in lubricating the engine. Either the carburetor or the fuel injection system atomize the fuel flow in the correct ratio for combustion. The fuel pump gets fuel from the tank to the engine.
5. The primary function of the alternator is to
(A) generate electric current to feed back to the battery.
(B)engage, spin, and disengage the flywheel.
(C)control engine emissions by regulating combustion.
(D) power the headlights and radio
5. (A) The primary function of the alternator is to generate electric current to feed back to the battery. The clutch, which is connected to the crankshaft, engages, spins, and disengages the flywheel. The emission control system controls engine emissions by regulating combustion. The battery powers the headlights and radio
A starter armature is being tested on a growler. If you hold a hacksaw blade or other similar strip of metal (not aluminum or stainless steel) lengthwise against the armature and then rotate the armature, the blade vibrates. What does this indicate?
(A) The field coils are grounded.
(B) The solenoid disk is burned.
(C) The armature is open.
(D) The armature is shorted.
6. (D) When a hacksaw blade or other similar strip of metal is held lengthwise against a starter armature, is rotated, and then vibrates, the armature is shorted. Any started windings will create a magnetic field that attracts the metal strip to the slot where the started winding is. When this happens, the strip of metal vibrates, causing a growling noise. "Opens" in the armature are found by using the meter on the growler.
7. An ohmmeter test of an electronic ignition pickup coil indicates an infinite reading.
What does this reading indicate?
(A) A normal circuit
(B) A short circuit
(C) An open circuit
(D) A grounded circuit
7. (C) An infinite reading on an ohmmeter test of an electronic ignition pickup coil indicates an open circuit. (An open circuit is also called an incomplete circuit.) A short circuit would be indicated by a lower than normal reading
The device used to check the rotor thickness and variation of a disc brake rotor is a
(A) torque wrench.
(B) dial indicator.
(C) micrometer.
(D) feeler gauge.
(C) The device used to check the rotor thickness and variation of a dise brake rotor is a micrometer.
Which gauge is used to check engine crankshaft endplay?
(A) Depth gauge
(B) Plastigauge
(C) Feeler gauge
(D) Micrometer
2. (C) A feeler gauge is used to check engine crankshaft endplay. It measures the clearance between the crankshaft and the main thrust bearing. This clearance determines the endplay of the crankshaft. A depth gauge is used to measure tire tread. A plastigauge is used to measure crankshaft bearing oil clearance. A micrometer is used to measure crankshaft journal diameter.
3. A transmission
(A) controls the speed of the engine.
(B) trades speed for power.
(C) transmits torque at an angle.
(D) trades power for speed.
(B) A transmission trades speed for power. It uses gear reduction to increase engine torque or turning force. During the time torque is increasing, speed decreases.
If a rear axle ratio is 4 to 1,
(A) the pinion gear has four times the number of teeth as the ring gear.
(B) the ring gear has four times the number of teeth as the pinion gear.
(C) the rear tire is four times larger than the brake drum.
D) the side gear has four times the number of teeth as the spider gear.
4. (B) If a rear axle ratio is 4 to 1, the ring gear has four times the number of teeth as the pinion gear. The pinion, which connects to the driveshaft, is the driving gear. The ring. which drives axles, is the driven gear. To calculate the gear ratio, divide the drive into the driven gear.
The motive power of the automotive cranking motor is created by the
(A) field poles attracting the laminated iron core of the armature.
(B) repelling force of like poles being formed in the armature opposite the field poles.
(C) starter neutral safety switch.
(D) starter drive.
5. (B) The motive power of the automotive cranking motor is created by the repelling force of like poles being formed in the armature opposite the field poles. When a starter is energized, the magnetic fields created in the armature and field coils produce the turning effect on the armature shaft. The starter drive engages the flywheel ring gear and cranks over the engine when the starter is energized.
6. If the transmission ratio is 3.29 to 1 and the differential ratio is 3.85 to 1, what is the final ratio?
(A) 7.05 to 1
(B) 0.56 to 1
(C) 12.67 to 1
(D) None of the above
6. (C) If the transmission ratio is 3.29 to 1 and the differential ratio is 3.85 to 1, the final ratio is 12.67 to 1. To calculate the final ratio of a transmission and differential, multiply the ratio of the transmission by the ratio of the differential: 3.29 × 3.85 = 12.67.
7. Ifair gets into the hydraulic brake system,
(A) brake application will be hard.
(B) it will have no effect.
(C) the brake pedal action will be spongy.
(D) the brake pedal will stick.
(C) If air gets into the hydraulic brake system, the brake pedal action will be spongy. Air is compressible and will cause a spongy or soft brake pedal action.
8. The proportioning valve in a hydraulic brake system
(A) reduces pressure to the front brakes.
(B) controls the brake warning switch.
(C) is used only on a drum-type brake system.
(D) reduces pressure to the rear brakes.
8. (D) The proportioning valve in a hydraulic brake system reduces pressure to the rear brakes. A proportioning valve is commonly used on a vehicle equipped with front disc and rear drum-type brakes. The valve reduces hydraulic pressure to the rear drum brakes to prevent rear wheel lockup and skidding during heavy brake pedal application.
9. Helical gears have
(A) slanted teeth.
(B)straight teeth.
(C)curved teeth.
(D)beveled teeth.
9. (A) Helical gears have slanted teeth. Spur gears have straight teeth. Hypoid and spiral gears have curved or beveled teeth.
10. A gear train that uses a sun gear, internal gear, and three pinion gears is known as
(A) bevel spiral pinion.
(B) worm and sector.
(C)planetary gears.
(D) differential gears.
10)C) A gear train that uses a sun gear, internal gear, and three pinion gears is known as planetary gears. Planetary gears are used in an automatic transmission. The three members are in constant mesh. They provide gear reduction and reverse without shifting. To obtain a gear reduction or reverse, one member must be held stationary by a band or clutch assembly. Worm and sector gears are used in some types of steering gear assemblies. Differential or spider gears are used in a rear-end assembly.