Electric class
Printed circuit boards often have two layers and as many as ___ to accommodate the complex circuitry.
16
You have a 4 ohm resistor and the battery is charged to 12 volts. How many amps will flow in the circuit?
3 amps
A circuit has 12 volts and 2 ohms. How many amps flow through it?
6
If a wire is described as being metric size of 8.0 it is:
8.0mm cross sectional area
Electricity can be produced by:
All of the above
Electromagnetic induction is applied in:
All of the above
Resistance measurements are used to check ______ or circuits against the manufacturer s specifications; for example, the resistance of sensors should be within the specified range.
Components
What is the most common automotive conductor material?
Copper.
Lead acid batteries create:
DC.
Hertz is the measurement of frequency and indicates the number of cycles per minute.
False
Networking makes it less efficient to add or modify system functionality through the addition of control units and the use of software updates.
False
The characteristics of AC are the fixed polarity of the applied voltage and the flow of charges in only one direction
False
Which of the following materials is widely used to build high-speed semiconductors?
Gallium-arsenide
What is one by-product of electricity flow?
Heat
It is important to understand that current ________ in all parts of a properly working series circuit.
Is the same
Tech A says that 18 AWG wire is larger than 12 AWG wire. Tech B says that the larger the diameter of the conductor, the more electrical resistance it has. Who is correct?
Neither A nor B
A disconnected battery is _____, and is _____.
Not doing work; still a source of energy
Every atom has a _________, with at least one positively charged _____ and, in most atoms, at least one _____ that has no charge.
Nucleus; proton; neutron
The ______ is the unit used to describe the amount of electrical resistance in a circuit or component.
Ohm
A(n) ________ is used to measure the amount of resistance in a component or circuit.
Ohmmeter
Electrical resistance is measured in:
Ohms
How many paths are there in a series circuit?
One
The formula for calculating power is:
P = V x I
The junction of a diode is called a:
PN junction.
Tech A says that NTC thermistors alter their resistance value inversely to temperature (as the temperature increases, resistance value decreases). Tech B says that PTC thermistors are used as throttle position sensors. Who is correct?
Tech A
Coloring a wire blue means that it is:
Variable.
When using current clamps, the DMM is set to read:
Volts.
For electrons to move in a circuit they need a complete pathway and:
a force to make them move.
'Energy' has the potential to:
do work.
Ohm's law tells us that it takes 1 volt to push 1 amp through how many ohms?
1 ohm
Acid flux is designed to be used on non-electrical metal joints such as radiators and must be removed after the soldering process so that the joint does not corrode.
True
Atoms with fewer electrons in the valence ring are the best conductors, with one electron being the best conductive material.
True
Conductive tracks on the surface of the printed circuits connect the leads of the electronic components to each other to form complex circuits.
True
Electricity can create a magnetic effect.
True
Ground is a term used by technicians to indicate the portion of the circuit that returns current flow to the negative side of the battery.
True
In a parallel circuit where the resistors in each branch are the same, the current flowing in each branch is also the same.
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
Often, harnesses on modern vehicles contain many wires, each terminating at crimped terminals inserted into connector or harness plugs.
True
Series-parallel circuits can be analyzed using the same electrical laws that apply to separate series or parallel circuits; you just have to apply the series laws to the series portion and the parallel laws to the parallel portion.
True
Simply stated, Kirchhoff s law states that current entering any junction is equal to the sum of current flowing out of the junction.
True
The higher the resistance, the less current (amps) that will flow in the circuit for any particular voltage.
True
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
The short causes abnormally high current flow in the circuit and may cause the circuit protection devices, such as fuses or circuit breakers, to open the circuit.
True
This process of converting light (photons) to electricity (voltage, which moves electrons) is called the photovoltaic (PV) effect.
True
To use wiring diagrams, an understanding of the symbols, abbreviations, and connector coding used in the diagrams is required.
True
True or False. Volts, amps, and ohms are the three basic units of electrical measurement.
True
Which factor below DOES NOT affect the resistance of a conductor?
Type of insulating material.
If voltage stays the same, but resistance goes up, what happens to amperage?
goes down.
When an atom has an equal number of protons and electrons it is said to:
have no overall charge.
In developing engine designs, manufacturers use thermocouples to measure the ___________ of components, such as spark plugs and exhaust systems.
High temperatures
Fiber optic cable has all of the following advantages over a conventional copper cable except:
It is expensive when compared to conventional cables.
Which of the following components can be programmed and are an integral part of other electrical components?
Microprocessors
When measuring resistance or voltage on a CANbus, always use a digital _____ and disconnect the _____ battery terminal when measuring resistance.
Multimeter; negative
Which of the following types of shielding is used in wiring to prevent electromagnetic interference (EMI)? Special plastic coated wires
Mylar tape
To solve for ohms, use the following formula:
R = V / A
_____ solder is used on electrical connections because it is much ____ likely to corrode the metals than _____.
Rosin flux; less; acid flux
Choose the correct statement.
Semiconductor devices are sensitive to heat and voltage spikes.
A thermocouple produces electrical energy when it is:
heated.
It is important to understand that the _____________ of the series voltage drops equals the supply voltage, as explained in Kirchhoff s voltage law.
Sum
Terminals can _____, leading to poor connections and voltage drops.
All of the above
Which of the following is an effect of the flow of electricity?
All of the above
What is an example of the heating effects of electricity?
All of these.
Total circuit resistance is equal to the ____ of the individual resistances.
Sum
Coloring a wire orange means that it is:
Switched to power.
The _____ is the unit used to describe how much current flow or how many electrons are flowing at a given point in 1 second when work is being performed for example, when a lamp is operating.
Ampere
All of the following statements are true except:
As technology has developed, usage of wires and cables has reduced.
All of the following statements about transistors are correct except:
They are made up of two sections of different polarity.
What is the most common use of speed control units in vehicles?
To control the fan speed in the HVAC system and the radiator
Most DMMs can measure milliamps or ______ directly through the meter.
10 to 20 amps
In calculating ohm's law using the following formula, _____________ : V = A * R
All of the above
Coloring wires on the wiring diagram:
Both A and B
Control modules monitor a number of inputs from sensors and circuits, process those data according to the information programmed into their memory, and send output commands to _______, which control the operation of various components and systems on the vehicle.
Both A and B
Optical fiber can be used to:
Both A and B
Tech A says that a twisted pair is two wires, twisted together, that deliver signals between common components. Tech B says that in many cases, wiring diagrams are set up with power on the top of the diagram and ground on the bottom. Who is correct?
Both A and B
Tech A says that some relays are equipped with a suppression diode in parallel with the winding. Tech B says that some relays are equipped with a resistor in parallel with the winding. Who is correct?
Both A and B
Tech A says that wiring diagrams are essentially a map of all of the electrical components and their connections. Tech B says that in many cases, each wire in wire harnesses use two colors; the first one is the solid color, and the second one is the stripe. Who is correct?
Both A and B
The __________ side of a circuit refers to the wires and components that originate at the positive post of the battery and end at either a switch or a load, whichever occurs first.
Both A and B
When soldering wiring, always use a(n):
Both A and B
The correct wire size for an application can be looked up on a wire size chart if you know the:
Both A and C
Technician A says wire size is very important. Technician B says there are two scales used to measure wire size. Who is correct?
Both Techs A and B
What materials make a good insulator?
Ceramic and plastic
Tech A says that while soldering wires, apply the solder to the wire opposite the soldering iron. Tech B says that you should heat the wire up until the plastic insulation melts. 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
Tech A says that a transistor has a single P-N junction. Tech B says that a transistor is a semiconductor device used as a switch and to amplify currents. Who is correct?
Tech B
Tech A says that if the specified fuse keeps blowing, it is generally okay to replace it with a larger fuse. Tech B says that a fusible link is one type of circuit protection device. Who is correct?
Tech B
Tech A says that it is best to use a knife or other type of sharp tool to cut away the insulation when stripping a wire. Tech B says that any issues with wiring are more likely to be with the terminals than with the wires themselves. Who is correct?
Tech B
Two technicians are discussing solder repair. Technician A says that solder should be applied to the soldering iron tip while soldering. Technician B says that the solder should be applied to the wire joint while soldering. Who is correct?
Technician B
Adding a resistor in series with a load will cause:
a drop in voltage across the resistor.
One function of a diode is to:
allow current flow in one direction only.
When more branches are added to a parallel circuit the overall circuit resistance:
decreases.
Electronic delay circuits are used to:
delay the turning on or off of electrical devices.
Wiring diagrams give information about:
electrical circuits and their components.
Excessive bare wire may:
expose the wire to a potential short circuit.
Electromagnetic induction can be increased by all of the following, EXCEPT:
increasing the temperature of the conductor.
Current in a series circuit:
is the same in all parts of the circuit.
An excess of electrons will give the atom a
negative charge.
The most effective and safest tool to use to strip insulation from electrical wire is a:
set of wire strippers.
If both wires in the twisted pair CANbus need to be repaired, it is best to:
stagger the joints.
A switch is used to:
turn current flow on and off.
Electrochemical energy is produced when:
two dissimilar metals are immersed in an acidic liquid.
