Electrical Systems - Final
Tech A says parallel circuits are like links in a chain. Tech B says total current in a parallel circuit equals the sum of the current flowing in each branch of the circuit. Who is correct?
Tech B
The _____________ monitors battery voltage and varies current flow through the rotor field circuit.
Voltage regulator
Lead acid batteries store:
DC
All of the following statements referring to driving lights are true except:
Driving lights turn off when the headlights are switched from low to high beam.
American manufacturers all use the American wire gauge scale.
False
Tech A says that if resistance stays the same and voltage goes up, then amperage goes down. Tech B says that if voltage stays the same and resistance goes down, then amperage goes down. Who is correct?
Neither A nor B
A compass is used to _______.
Show that when energized, the relay winding produces a magnetic field
The magnetic fields from both solenoid windings work together to attract the _________ toward the main starter terminals in the solenoid cap.
Solenoid plunger
Potentiometers are mechanical variable resistors with ____ connections, ______.
Three, two fixed and one movable
Care should be taken when testing relays and solenoids to ensure that cables are not shorted to ground and the engine is not accidentally cranked over.
True
Which component in the alternator controls the strength of the magnetic field of the rotating magnet?
Voltage regulator
On some vehicles, the power train control module (PCM) is able to control the level of _________at which the battery is charged.
Current flow, Voltage
Which of the following lights use flashing control and also warn other road users if the vehicle is parked in a dangerous position on the side of the road?
Hazard warning lights
It is important to understand that current flow is ____________ to resistance.
Inversely proportional
Which of the following is NOT a typical electrical problem that can cause starting system problems?
Engine mechanical fault
A so-called three-phase "bridge" rectifier has a minimum of ______ to rectify the AC output of the stator windings to DC output from the rectifier.
6 diodes
Electromagnetic induction is applied in _____.
Alternators, Ignition coils, Some sensors on the vehicle
Tech A says that some turn signals are flashed by a flasher can. Tech B says that some turn signals are flashed by the BCM. Who is correct?
Both A and B
When the engine is not running, current to operate electrical circuits is supplied by the:
Battery
Tech A says that the size of the wire determines the amount of current flow that the conductor can handle. Tech B says that an engine cranking voltage drop test is the most reliable way to detect high resistance that exists within the starting circuit. Who is correct?
Both A and B
Tech A says you should use a rosin core solder when repairing electrical circuits. Tech B says you should not overheat the repair. Who is correct?
Both A and B
__________ is a process of converting AC into the DC that is required by the battery and nearly all of the automobile systems.
Rectification
Tech A says a flasher works just like a fuse. Tech B says flasher cans are mechanical devices while flasher controls are generally electronic devices. Who is correct?
Tech B
Tech A says never disconnect sensors before conducting resistance checks. Tech B says automotive test lamps should not be used on digital circuits because they draw too much current and can overload the circuit. Who is correct?
Tech B
Automotive test lamps should not be used on digital circuits because they draw too much current and can overload the circuit.
True
Batteries may be tested for sufficient state of charge by testing the electrolyte for acid content.
True
Generally, three-phase motors or alternators produce more output than single-phase motors or alternators because they can maintain a much more even voltage compared to single-phase AC.
True
Increasing the strength of the magnetic field increases the value (voltage output) of the induced EMF.
True
Be careful of the chart you use, because many of them allow up to a ____ voltage drop over the length of the wire, which is more than is allowed in most automotive circuits.
0.1
Be careful of the wire size application chart you use, because many of them allow up to a ____ voltage drop over the length of the wire, which is more than is allowed in most automotive circuits.
0.1
Tech A says that you should never jump-start a frozen battery. Tech B says that a frozen battery can explode, causing injury, when jump-started. Who is correct?
Both A and B
Electronic delay circuits are used to:
Delay the turning off of devices
The electrolyte in an automotive lead acid battery is:
Dilute sulfuric acid.
Alternators use ______ to create current flow to charge the battery and run the electrical accessories.
Direct current
The _____ resistance fault would cause an abnormally _____ current flow in the circuit and may cause the circuit protection devices, such as fuses or circuit breakers, to ____ the circuit.
Low, High, Open
The alternator converts:
Mechanical energy into mechanical energy
Vehicle alternators are designed for use on what type of ground system?
Negative
Tech A says AC stands for alternating voltage. Tech B says DC is used in electric motors on most hybrid vehicles. Who is correct?
Neither A nor B
A disconnected battery is _____, and is _____.
Not doing work; still a source of energy
No matter what direction the current is flowing in the stator windings, the diodes in a rectifier only allow current to flow into the rectifier and out of the rectifier in ____________ direction(s).
One
In a three-phase alternator, as the rotor spins, each time the rotating magnetic field changes from north to south and south to north, the polarity of each phase winding ___________.
Reverses
A load test is testing the battery's ability to produce the high starting current, while maintaining enough voltage to operate the ignition and electronic control systems.
True
Many of the testers have integrated printers, and for the battery to be warranted, a printout of the test result has to accompany the replaced battery.
True
Many vehicles connect the chassis and body to the negative battery terminal, which means most of the metal components on the vehicle are grounded.
True
The voltage regulator's job is to control the output of the alternator so that the system voltage is maintained within specified limits.
True
Atoms that gain electrons become positively charged.
False
Tech A says that if the brake light switch is open, neither brake light will illuminate. Tech B says that the backup lights operate when taillights operate. Who is correct?
Tech A
The starter motor converts:
electrical energy into mechanical energy
When the starter motor starts under load:
it draws high current and produces maximum torque
How many phases does a typical automotive alternator have?
Three
In some cases, it may be possible to use a ____ memory minder or memory saver to maintain the vehicle's memory while the vehicle battery is disconnected.
9-volt
The revolving component of the starter is the:
Armature
What are the two main components of an electric motor?
Armature and the field
If the vehicle was equipped with a standard transmission, then a clutch switch was installed such that it was _____ by ___________.
Closed; depressing the clutch pedal
Resistors are commonly used to control the _____ that reaches various components
Both A and B
Tech A says that LED brake lights illuminate faster than incandescent bulbs. Tech B says that LED brake lights have more visibility and last longer. Who is correct?
Both A and B
Tech A says that a light intensity meter is used to measure the brightness of headlights. Tech B says that some headlights can automatically adjust side to side when the vehicle is cornering. Who is correct?
Both A and B
Tech A says that a voltage drop test is typically used to find excessive resistance in a circuit. Tech B says that high resistance creates heat at the point of resistance in the circuit. Who is correct?
Both A and B
Tech A says that some automotive lightbulbs have more than one filament inside. Tech B says that before aligning headlights, make sure the tires are inflated properly. Who is correct?
Both A and B
Tech A says that some brake lights get power from the brake switch through the turn signal switch. Tech B says many turn signals use amber lights. Who is correct?
Both A and B
Tech A says that some starters use gear reduction to improve efficiency. Tech B says that a starter converts electrical energy to mechanical energy. Who is correct?
Both A and B
As the starter motor and engine cranking speed increase, the current draw ____ and quickly_____ once the engine reaches full cranking speed.
Decreases; stabilizes
Which lightbulbs are very efficient and sensitive, and can be damaged even by finger oil residue?
Halogen lamps
Mechanical problems that may cause starting system problems include seized pistons or bearings and___________________________.
Hydrostatic lock from liquid in the cylinder(s), Incorrect ignition or valve timing, A seized alternator
Which of the following statements describes the purpose of backup lights?
It provides the driver with vision behind the vehicle.
Which lights are wired in parallel with the taillights and operate whenever the taillights are switched on?
License plate lights
The device which is used to measure the amount of resistance in a component or a circuit is a(n):
Ohmmeter
The ____ of the starter motor engages with the _____, and the starter motor then rotates to turn over, or crank, the engine.
Pinion; flywheel ring gear
Which of the following alert(s) the other drivers of a change in direction?
Red or amber turn signals
The solenoid plunger movement allows a very large current to flow from the battery to the starter motor, __________.
Rotating the armature, Rotating the drive pinion gear, Causing the crankshaft to rotate
The ______________ provides a method of rotating the crankshaft of the internal combustion engine (ICE) to begin the combustion cycle.
Starting system
Tech A says that a voltage drop of 0.8 volts on the starter ground circuit is within specifications. Tech B says that high starter draw current could be caused by a spun main bearing in the engine. Who is correct?
Tech B
Tech A says that a voltage drop on the ground side of a bulb won't affect its brightness because the electricity has already been used up. Tech B says that a voltage drop is a good way to determine if there is unwanted resistance in a circuit. Who is correct?
Tech B
Tech A says that if the oil pressure warning light is on, the first thing you should do is replace the oil pressure sending unit. Tech B says that if a bulb is dim, you should perform a voltage drop test on the power and ground side of the bulb. Who is correct?
Tech B
All of the following statements with respect to the function of headlights are true except:
They are connected in series with each other.
The power source pushes a flow of electrons (current flow), measured in amps, when the switch is in the closed position, completing the path.
True
When the engine starts and is able to run on its own, the operator usually releases the key and the solenoid spring withdraws the pinion gear from the ring gear and brings the armature to a halt.
True
Wiring harnesses run _____.
Around the engine bay, Through the dash and interior cabin, To the rear of the vehicle
What is all matter composed off?
Atoms
Tech A states that DMMs come in a variety of layouts and qualities. Tech B states that DMMs and test leads also should have a CAT rating listed on the front. Who is correct?
Both A and B
Tech A states that a diode bridge gets its name from two diodes in series, bridged with a wire. Tech B states that in a three-phase alternator, one side of each stator winding is connected to one of the bridges. Who is correct?
Both A and B
Two technicians are discussing electron flow. Tech A says that in "conventional theory" current is believed to flow from positive to negative. Tech B says that in "electron theory" current is believed to flow from negative to positive. Who is correct?
Both A and B
Two technicians are discussing solder wire repair. Technician A says that electrical tape can be used to cover the joint. Technician B says that heat shrink tubing can be used to cover the joint. Who is correct?
Both A and B
When resistors of the same resistance are connected in series, the voltage drop across the first resistor is _________ the voltage drops across each of the other resistor.
Equal to
A battery can have its lifetime shortened by which of the following?
Excessive vibrations, Corrosion, Overcharging
An atom with more electrons than protons has an overall positive charge and is called a positive ion.
False
Voltage drop can be measured across components, connectors, or cables accurately even when current is not flowing.
False
The most effective and safest tool to use to strip insulation from electrical wire is a:
Set of wire strippers
Battery temperature plays an important role in the performance of a battery
True
Tech A says that an alternator should be replaced whenever there are electrical or mechanical faults. Tech B says that alternator faults include no charge, undercharge, or overcharge conditions. Who is correct?
Both A and B
Overcharging a battery is called:
Gassing
Electricity can perform work if it is directed at objects that can _______ the moving particles, such as lights and electric motors.
Extract energy form
In the Delta method, the windings are connected in the shape of a square.
False
Regardless of the way it is produced, electricity is always the movement of protons in a conducting circuit.
False
To identify their value, many resistors are marked with _____ colored bands
Four or five
Two technicians are discussing amperage in a series circuit. Technician A states that adding resistors in series will decrease circuit amperage and could blow a fuse. Technician B states that amperage will be the same at all points in a series circuit. Which technician is correct?
Tech B
An ignition coil can be described as a step-up transformer
True
If the wire is wound into a coil, the magnetic fields combine to create a stronger and denser magnetic field, with a north and a south pole, just like a permanent magnet.
True
In a Wye type stator, each winding is always part of a complete circuit, and when current is flowing, it is always flowing through two series windings at the same time.
True
Voltage drop can be measured across _____, but current has to be flowing to get an accurate measurement.
Components, Connectors, Cables
Out-of-circuit tests are often preferred, as they usually provide the opportunity to test the component under load or during operational conditions.
False
Polarity-sensitive components always have the polarity marked on both connections to ensure that the user connects them into the circuit correctly.
False
A faulty circuit may have_______.
High resistance, No continuity
Every atom has a _________, with at least one positively charged _____ and, in most atoms, at least one _____ that has no charge.
Nucleus, Proton, Neutron
_______ circuits are found in vehicles, such as in dash light dimmer circuits, although they are not as common as _______ circuits.
Series-parallel; parallel
Tech A says that a 12-volt battery has six cells. Tech B says that the more plates a cell in a battery has, the more voltage it creates. Who is correct?
Tech A
Two technicians are discussing a parasitic load test. Technician A says that the parasitic load is measured with an ammeter. Technician B says that the parasitic load is measured with a voltmeter. Who is correct?
Tech A
Two technicians are discussing batteries. Technician A says that lead acid batteries must use plates of two different materials. Technician B says that the plates must be of the same materials. Who is correct?
Tech A
Tech A says that a relay is a one-way electrical check valve used in alternators to change AC into DC. Tech B says that a relay uses electromagnetism to open or close a switch. Who is correct?
Tech B
Technician A says that solder typically used in automotive electrical applications is 20% Tin and 80% lead. Technician B says soldered wire repairs should have a good mechanical connection as well as a good electrical connection. Who is correct?
Technician B
Rheostats are commonly used in _____.
Both A and B
Tech A says a voltage drop of 0.4 volts is acceptable between the power supply and the load. Tech B says a voltage drop across a(n) individual component should be less than 0.2 volts. Who is correct?
Both A and B
The alternator must be operated with the battery disconnected or with the terminals at the back of the alternator disconnected.
False
What is one by-product of electricity flow?
Heat
High-voltage systems have a number of advantages over low-voltage systems, including:
Less susceptibility to voltage drop, Reduced current flow, Smaller diameter conductors
If the amperage is low, then you know that one of two conditions is present either the voltage is ______ or the resistance is ______.
Low, High
Tech A says that a voltage drop on the ground side of a bulb won't affect its brightness because the electricity has already been used up. Tech B says that a voltage drop is one way to determine if there is unwanted resistance in a circuit. Who is correct?
Tech B
Tech A says that batteries should be charged as fast as possible. Tech B says that the ideal charging rate is the CCA divided by 70. Who is correct?
Tech B
Tech A says when doing a voltage drop test, the voltmeter needs to be set to ohms. Tech B says current has to be flowing to do a voltage drop test. Who is correct?
Tech B
Two technicians are discussing a series circuit with four resistors of various resistances. Tech A says that current flow will be different in each resistor. Tech B says that current flow will be the same in each resistor. Who is correct?
Tech B
Two technicians are discussing battery charging. Technician A says that it is better for the battery to be fast charged. Technician B says that it is better for the battery to be slow charged. Who is correct?
Tech B
Dirt on top of the battery causes premature self-discharge of the battery as current "leaks" across the path of dirt or grime.
True
When calculating current flow in a parallel circuit that has 4 resistors, you would:
add the current flow for each resistor together.
A variable resistor:
has a movable arm that swipes across a coil that has less resistance at one end and more at the other.
When working on a parallel circuit, all these are true EXCEPT:
the voltage needs to go up as circuits are added.
What type of water should you use to top up battery electrolyte levels?
De-mineralized or distilled.
If the pressure (_____) stays the same but the restriction (_____) doubles, then the electrons (_____) will be reduced by half.
Volts, Ohms, Amps
Tech A says a battery charger has to have a transformer and a rectifier to produce DC volts. Tech B says you can run an AC motor on DC volts. Who is correct?
Tech A
What is the popular name for an electrochemical cell?
A battery
If only one side of the fuse lights the test lamp, then the fuse is:
Blown
Tech A says you should never strip wires with a knife or other sharp tool. Tech B says it's ok to repair wires with solderless connectors if done properly. Who is correct?
Both A and B
Atoms with fewer electrons in the valence ring are the best conductors, with one electron being the best conductive material.
True
To tell if the surface of the battery needs to be cleaned, use a digital volt-ohmmeter (DVOM) set to volts to measure the voltage on the surface of the top of the battery.
True
