AUT - 120 Final Exam

The maximum voltage drop for the insulated circuit [battery positive to starter solenoid] is typically about _____ volt.

0.6

A technician is checking a circuit with excessive resistance. The current flow through the circuit should be 10 amps, but a check with an ammeter measures only 6 amps. The technician measures a voltage drop of 1.0 volts across the switch terminals when the circuit is turned on. What is the resistance of the switch?

1/6 ohm

If a 100 microfarad capacitor is charged off of a 12 volt battery, how many volts will be present between the terminals of the capacitor?

12 volts

The electrical system of a modern automobile runs at _____ volts when the engine is running.

14.0

The reference voltage [Vref] sent to most sensors ranges from _____ to _____ volts.

5.0, 9.0

Some multimeters display RMS readings for ______.

AC circuits

A rotating magnetic field inside a set of stationary conducting wires is a simple description of a(n) ______.

AC generator

Which of the following is NOT made of semiconductor material?

Magnetic pulse [PM] generator

The two types of semiconductor materials are P-type and ______

N-type

Which of the following is NOT part of routine battery inspections and maintenance?

Refill the electrolyte level with clean electrolyte

Which of these statements is NOT a true conclusion from a battery load test?

The battery should be charged and then retested because it dropped below 9.6 volts and rose above 12.4 volts when the load was removed

What type of test equipment is needed to perform a charging system current output test?

a VAT with a carbon pile

Technician A says 42-volt automotive electrical systems can use smaller wires to supply the same amount of power to electrical accessories. Technician B says a 42-volt electrical system is very dangerous and can kill you if your skin comes into contact with exposed wiring. Who is correct?

a only

Technician A says a battery strap or carrier should be used whenever a battery is lifted. Technician B says when a battery is removed, the positive cable should be disconnected first. Who is correct?

a only

Technician A says a starter no-load test is conducted with the starter in a bench vise. Technician B says the battery must have a minimum voltage of 9.6 volts during the test. Who is correct?

a only

Technician A says diodes are used to rectify the voltage produced from an AC generator. Technician B says a zenerdiode protects circuit components from voltage spikes. Who is correct?

a only

The _____ changes analog signals produced by sensors into digital signals that the computer can use to process and store data.

a to d converter

The motor/generator in a hybrid vehicle ______.

all answers are correct

Which of the following is a semiconductor?

all answers are correct

Which of the following requires a high-speed bus?

antilock brakes

Technician A says an a circuit has the regulator on the positive side of the field coil. Technician B says on an isolated field circuit, the regulator may be on the negative or the positive side. Who is correct?

b only

Voltage regulators are being discussed. Technician A says charging voltage is decreased when the battery temperature is low because the battery cannot accept high charging rates at low temperatures. Technician B says the voltage regulator increases the current flowing through the field coil when the battery voltage is low. Who is correct?

b only

Which of the following is associated with voltage frequency?

both "cycle" and "hertz"

Sulfation of battery plates can cause _____.

both "lower specific gravity" and "reduced reserve power in cold weather"

Before adjusting drive-belt tension, Technician A checks for proper pulley alignment. Technician B looks up the specified belt tension in the vehicle's service manual. Who is correct?

both a and b

Energy storage is being discussed. Technician A says a battery stores energy chemically. Technician B says a capacitor stores energy in an electrostatic field between two electrodes. Who is correct?

both a and b

Hybrid vehicles are being discussed. Technician A says some hybrid vehicles use a motor/generator that is connected to the crankshaft by a drive belt. Technician B says the motor/generator on a hybrid vehicle is located at the flywheel. Who is correct?

both a and b

Technician A says a Hall-effect switch uses a semiconductor, permanent magnet, and trigger wheel to measure shaft speed. Technician B says an engine coolant temperature sensor is basically a thermistor. Who is correct?

both a and b

Technician A says some types of voltage sensors provide input to the computer by modifying or controlling a constant, predetermined voltage signal. Technician B says some types of voltage sensors provide a voltage generating signal. Who is correct?

both a and b

Technician A says the amount of electricity produced by an AC generator depends on the strength of the magnetic field. Technician B says it depends on the speed at which the magnetic field moves past the wires. Who is correct?

both a and b

Technician A says the purpose of the solenoid is to engage the starter pinion into the flywheel's ring gear. Technician B says the solenoid energizes the starter motor by closing the electrical circuit from the battery to the motor. Who is correct?

both a and b

Technician A says uses an ohmmeter to measure resistance of a component. Technician B uses a voltmeter to measure voltage drop. Who is correct?

both a and b

Technician A touches a good ground immediately before touching a computer module. Technician B wears a grounding wrist strap before touching the computer electrical connections and computer case. Who is correct?

both a and b

Technician A uses a voltmeter to check circuit resistance. Technician B uses an ohmmeter to check circuit resistance. Who is correct?

both a and b

The teeth on a starter drive are worn excessively. Technician A says to replace the starter drive. Technician B says to check the flywheel. Who is correct?

both a and b

While discussing armature testing, Technician A says to test for shorts, place the armature in a growler and hold a thin metal blade parallel to the armature. Technician B says an ohmmeter can be used to test for shorts. Who is correct?

both a and b

When testing the high-voltage circuits on a hybrid vehicle, a _____type meter and test leads must be used.

cat III

A(n) _____is often used to prevent damage to electronic components from the voltage spikes produced when electromagnetic coils are turned off

clamping diode

Starting in model year 2008, what type of communication protocol is required for diagnostics?

class C (CAN)

Which of the following would NOT cause excessive current draw by the starter motor?

excessive resistance in the battery cables

The number of charge/discharge cycles an ultracapacitor can supply to the hybrid traction motor system is approximately ______.

infinite

Which of the following tests would be performed to check for high resistance in the positive battery cable?

insulated circuit resistance test

Which of the following is NOT a type of actuator?

magnetic pulse generator

Technician A says when a battery is charging, it changes chemical energy into electrical energy. Technician B says when a battery is being discharged, it changes electrical energy into chemical energy. Who is correct?

neither a nor b

The unit for measuring electrical resistance is _____.

ohms

Voltage regulator circuitry in the computer control module controls AC generator output by ______.

pulsing current flow to the rotor field windings on and off to create a correct average field current supply

All the following are variable resistors EXCEPT:

resistor wire

Semiconductors are made of ______.

silicone

What device pushes the starter pinion gear into mesh with the ring gear when the ignition switch is in the start position?

solenoid plunger

Which of the following does NOT use a magnetic pulse generator [PM generator]?

throttle position sensor