Final Questions
The following diagram represents a/an _______________ transformer
Isolation
What is the most common machine wire type?
THHN
For an electrolytic capacitor, the negative lead connects to?
The lower voltage
Which of the following is true of a three-wire motor control?
The motor does not restart when power is restored after a power failure.
What is the main purpose of the centrifugal switch in a capacitor-start motor?
It is closed at start-up to place the capacitor in series with the Start winding which creates the phase shift needed to rotate the rotor.
How does the overload of a motor provide protection when current exceeds a predetermined value?
It opens a normally closed contact.
The section of a technical report which summarizes the report's contents is called what?
Abstract
Which of the following is used to measure a current?
Ammeter
A wire's current carrying limit is known as what?
Ampacity
What is a Farad a unit for?
Capacitance
Overload protection is designed to protect the ___________ by disconnecting it from the power source when an overload is sensed.
Electric Motor
An electric motor is used to change?
Electrical Energy into Mechanical Energy
The rate at which energy is consumed in a circuit is called.
Electrical Power
A person with a serious electrical injury should be moved
Only if they are in immediate danger
How does a three-phase motor windings get connected for low-voltage?
Parallel
Which article of the NEC covers definitions?
Article 100
What does this symbol designate?
Fuse
What does a filled triangle represent in a fluid power diagram?
Hydraulic Flow
This type of drawing represents a three-dimensional object using several two-dimensional views of the object.
Orthographic
What is Watt's Law?
P=I^2 x R
The low voltage windings of a three phase motor are connected in _________.
Parallel
An ohmmeter is used to measure
Resistance
What is voltage?
An Electromotive Force or potential difference expressed in volts
What article in the National Electric Code covers motors, motor branch-circuit and feeder conductors and their protection?
Article 430
A detached garage has a breaker panel which is connected to a breaker in the house breaker panel. What type of circuit is the garage breaker panel considered?
Branch
A _________ fire extinguisher should be used on an electrical fire
Class C
Raceways are not used to ___________.
Control the amount of voltage allowed in an electrical distribution system.
Every digital multimeter can measure which three basic elements?
Current, Voltage, and Resistance
What are linear dimensions usually expressed in?
Decimal or Fractional Units
If a switch is described by the term DPDT, what does this stand for?
Dual Pole, Dual Throw
NFPA 70E is a regulation that provides guidelines and details for ________.
Electrical Safety
In the diagram above, what type of interlocking is utilized to prevent forward and reverse from working simultaneously?
Electrical and Mechanical interlocking
A LOTO procedure should be performed to lock out energy when working o which of the following systems?
Electrical, Fluid Power, and Mechanical
What is the process in which a magnetic field activates voltage in a coil?
Electromagnetic Induction
Resistance opposes the flow of what?
Electrons
The period of a given AC waveform is the time for one:
Full Cycle
What are examples of overcurrent protection devices?
Fuse; Breaker
In residential structures, GFCI outlets are required in:
Garages
Based on NEC color-coding requirements, ground conductors must be designated by ________ and neutral conductors by ________.
Green; White
A safety Data Sheet (SDS) provides information about first aid measures, stability and reactivity, and _____?
Handling and Storage
In it's current state, what lights are lit?
Idle
What device is placed between solar panel and the power line to convert DC into AC?
Inverter
In an AC circuit, if resistance remains the same and voltage is doubled, the current
Is Doubled
Which of the following is true of a control transformer?
It has two input coils and one output coil.
What changes can be made to the circuit to cause the motor to reverse direction?
Switch T1 and T3
How do you change the direction in a split-phase motor?
Switch the connection to the starting winding
What does a thick line represent in a schematic diagram?
The flow of current.
Which of the following is NOT true of a title block?
The format is the same from company to company.
Which of the following is true of two-wire control for a motor?
The motor will restart automatically when power is restored after a power failure.
Jogging is a type of motor control in which what happens?
The motor's rotation is moved (bumped) slightly.
A wire's gauge is a measure of what?
The number of dies the wire was drawn through.
Which is true of an induction motor?
There is no physical electrical connection to the rotor.
Motors are normally protected from overload by a __________ device.
Thermal
Wire labelled THW means it has what characteristics?
Thermoplastic insulated, heat resistant, damp and wet location.
What can happen if bolts and nuts are not properly torqued?
They wear out quickly and can cause failure
11. GFCI devices are used for what purpose?
To prevent a person from being electrocuted
What is happening in the circuit when a fuse fails?
Too much current for too long of a time.
What tool is used to measure the turning force when tightening a fastener?
Torque Wrench
If you inhale phenolic fumes what would happen to you?
Trouble Breathing
Which electrons are involved in current flow?
Valence Electrons
What aspects of a waveform does an oscilloscope display?
Voltage versus Time
Is it true that polarity must be observed when installing an electrolytic capacitor in a circuit?
Yes
What resistance must Rs be for 1 amp to be supplied by the power supply?
12 Ohms
The NEC states that a non-metallic sheathed cable be secured by staples or straps within ___________ from every cabinet, box, or fitting.
12 inches
The approximate peak-to-peak value of an alternating current signal that measures 240V RMS is?
678.8 volts
What is the total resistance of the circuit?
9 kOhms
If a 500 ohm resistor has 1.5 mA flowing through it, how much voltage is across the resistor?
0.75 Volts
If four 100 ohm resistors are placed in series and then connected to a 40 V DC power supply, what is the power dissipated by one of the resistors?
1 Watt
A 1000 ohm resistor has 20 volts dropped across it, what is the minimum size the resistor should be?
1/2 Watt
If four 1000 ohm resistors are placed in parallel and then connected to a 100V AC power supply, what is the power dissipated by one of the resistors?
10 Watts
What would be the appropriate ohmmeter setting to measure a 4700 ohm resistor?
20K ohm
If four 1000 ohm resistors are in parallel, what is their total resistance?
250 Ohms
An electronic device runs on a 36-volt supply and takes 11 amps. What is it's power?
396 Watts
What is the total for a 560 ohm, 1k ohm, and 3.3k ohm resistors in series?
4,860 ohms
What resistance value is yellow, brown, black, gold?
41 ohms, 5% tolerance
Find the total resistance in a parallel circuit with three resistances of 10ohm, 20ohm, and 30ohm.
5.45 ohms
If the voltage source supplies 260 volts and the resistance measures 5 ohms, the current is
52 Amps
Which of the following must be provided by chemical manufacturers, distributors, and importers to anyone who will work with these potentially dangerous materials?
Safety Data Sheet (SDS)
A water meter is installed into the incoming copper water pipe in a house. There is copper water pipe on each side of the water meter. A wire is placed around the water meter connecting the inlet copper pipe to the output copper pipe. What is the main purpose of this wire?
To bond the inlet to the outlet copper water pipes around the water meter.
What is the purpose of the capacitor in a capacitor-start motor?
To create a phase shift between the run winding and the start winding.
Who is responsible for enforcing the NEC?
Local authority having jurisdiction.
What safety practice is used to prevent equipment from being energized?
Lockout/ Tagout
What is the direction of electron movement across poles
Negative to positive
What does OSHA stand for?
Occupational Safety & Health Administration
An interlock prevents two of the three phases on a reversing motor from shorting by doing what?
Preventing the opposite coil from shutting its contacts when a coil is energized.
The transformer winding to which the line is connected is called the _________ winding
Primary
When measuring an AC voltage with a digital multimeter, what value is typically shown on the display?
RMS Value
A resistor with a value of 23 k ohms +/- 5% will be colored?
Red, Orange, Orange, Gold
Every digital multimeter can measure three basic thing- current, voltage, and __________.
Resistance
How do you reverse the direction of rotation in the split-phase motor?
Reverse the polarity of the start winding.
When the jog push button is pressed, what light(s) will be on?
Run
What is the description for the following symbol?
SPDT switch
You come across a fellow employee who is being electrocuted by becoming attached to a live electrical circuit, what is the first thing you should do?
Shut off the circuit
The following would be considered physical hazards in the workplace.
Slippery floors and cluttered walkways
What are the characteristics of a small diameter wire versus a large diameter wire?
Small diameter wire has a larger ampacity than large diameter wire.
A motor _______________ is a motor controller that includes overload protection
Starter
A motor __________is a motor controller that includes overload protection
Starter
If R2 were to fail open, the current through R3 does what?
Stays the same at 50 mA
The winding ratio of a _______________ transformer has a rating of 3:1 winding ratio
Step-Down
Which of the following is an example of an input into a motor control circuit?
Switch