Digital Multimeter Units 1-5 Flashcards
A “digital multimeter (DMM)” is a test tool used to measure _____ or more electrical values.
Answer 1: two
Answer 2: three
Answer 3: four
Answer 4: five
two
Electrical Measurement Safety
“Personal protective equipment (PPE)” is clothing and/or equipment worn by a technician to reduce the possibility of injury in the work area.
Answer 1: True
Answer 2: False
True
Personal Protective Equipment
A “transient voltage” (voltage spike) is a(n) _____ voltage in an electrical circuit.
Answer 1: constant, unchanging
Answer 2: temporary, undesirable
Answer 3: unstable, highly flammable
Answer 4: none of these
temporary, undesirable
International Electrotechnical Commission (IEC) 61010 Safety Standard
Electrical circuits are _____ to safeguard equipment and personnel against the hazards of electric shock.
Answer 1: bonded
Answer 2: jumpered
Answer 3: de-energized
Answer 4: grounded
grounded
Grounding
“Lockout” is the process of removing the source of electrical power and installing a _____ that prevents the power from being turned on.
Answer 1: bar
Answer 2: lock
Answer 3: key
Answer 4: all of these
lock
Lockout/Tagout
“Tagout” is the process of placing a _____ tag on the source of electrical power, which indicates that the equipment may not be operated until the tag is removed.
Answer 1: no trespassing
Answer 2: yellow
Answer 3: time-out
Answer 4: danger
danger
Lockout/Tagout
An “_____” is a discharge of electric current across an air gap.
Answer 1: electric arc
Answer 2: arc flash
Answer 3: arc blast
Answer 4: none of these
electric arc
Arc Blast Safety
The “flash protection boundary” is the distance at which personal protective equipment (PPE) is optional to prevent burns when an arc occurs.
Answer 1: True
Answer 2: False
False
Arc Blast Safety
DMMs can be broadly classified as _____ DMMs.
Answer 1: general-purpose
Answer 2: standard
Answer 3: advanced
Answer 4: any of these
any of these
DMM Types
Characteristics of a general-purpose DMM include _____.
Answer 1: the ability to measure two or more basic electrical quantities
Answer 2: a continuity test mode
Answer 3: a display usually limited to three digits
Answer 4: all of these
all of these
DMM Types
A standard DMM is useful for _____.
Answer 1: taking measurements
Answer 2: troubleshooting
Answer 3: a and b
Answer 4: none of these
a and b
DMM Types
An advanced DMM can be used for standard DMM applications, troubleshooting complex problems, and identifying conditions that lead to _____.
Answer 1: problems
Answer 2: short circuits
Answer 3: ground faults
Answer 4: arc flashes
problems
DMM Types
fA DMM is commonly used for measuring electrical quantities such as _____ in electrical and electronic circuits.
Answer 1: voltage
Answer 2: amperage
Answer 3: resistance
Answer 4: all of these
all of these
DMM Usage
DMMs commonly use _____ to represent a quantity or term for quick recognition.
Answer 1: scientific notation
Answer 2: standard abbreviations
Answer 3: a and b
Answer 4: none of these
standard abbreviations
DMM Usage
The minimum and maximum quantity that a DMM can safely and accurately measure is known as the “_____ range.”
Answer 1: measuring
Answer 2: capture
Answer 3: amplitude
Answer 4: sample
measuring
DMM Usage
The “trigger level” is the _____ level at which the DMM counter is triggered.
Answer 1: constant
Answer 2: variable
Answer 3: fixed
Answer 4: none of these
fixed
DMM Usage
Digital multimeters (DMMs) display readings as exact alpha-numeric values.
Answer 1: TRUE
Answer 2: FALSE
FALSE
Digital Displays
Errors can occur when reading the digital display of a DMM if _____ displayed are not properly interpreted.
Answer 1: prefixes
Answer 2: symbols
Answer 3: decimal points
Answer 4: any of these
any of these
Digital Displays
A bar graph reading on a display is updated approximately _____ times per second depending on the DMM type.
Answer 1: 20 to 30
Answer 2: 25 to 35
Answer 3: 30 to 40
Answer 4: 35 to 40
30 to 40
Digital Displays
The bar graph is used when quickly changing signals cause the numerical display to flash or when a change in the circuit is too rapid for the numerical display to indicate.
Answer 1: TRUE
Answer 2: FALSE
True
Digital Displays
A numerical reading on a display cannot indicate contact bounce because most displays require more than _____ ms to update measurements.
Answer 1: 200
Answer 2: 250
Answer 3: 300
Answer 4: 350
250
Digital Displays
DMMs have a high _____ when set to measure alternating-current voltage.
Answer 1: output capacitance
Answer 2: input capacitance
Answer 3: output impedance
Answer 4: input impedance
input impedance
Ghost Voltages
“Ghost (stray) voltage” is a voltage reading on a DMM that is not connected to a(n) _____ circuit.
Answer 1: alternating-current
Answer 2: direct-current
Answer 3: multiwire branch
Answer 4: energized
energized
Ghost Voltages
Some meters include a _____ alternating-current voltage measurement setting.
Answer 1: low-capacitance
Answer 2: high-capacitance
Answer 3: low-impedance
Answer 4: high-impedance
low-impedance
Ghost Voltages
DMM advanced features are helpful when troubleshooting a problem(s) such as _____.
Answer 1: improper frequencies
Answer 2: overheated neutrals
Answer 3: intermittent problems
Answer 4: all of these
all of these
DMM Advanced Feature Applications
“Autorange mode” is a DMM mode that automatically selects the range with the best _____ for the measurement.
Answer 1: resolution
Answer 2: accuracy
Answer 3: bar graph
Answer 4: a and b
a and b
DMM Advanced Feature Applications
“MIN MAX Recording mode (MIN MAX)” is a DMM mode that captures and stores the lowest and highest measurements for _____.
Answer 1: historical purposes
Answer 2: accurate billing
Answer 3: later display
Answer 4: comparative analysis
later display
DMM Advanced Feature Applications
“Average Recording mode” is a DMM MIN MAX recording mode that continually calculates the true average of all readings taken each hour.
Answer 1: TRUE
Answer 2: FALSE
FALSE
DMM Advanced Feature Applications
“Relative mode (REL)” is a DMM mode that records a measurement and displays the difference between that reading and subsequent measurements.
Answer 1: TRUE
Answer 2: FALSE
TRUE
DMM Advanced Feature Applications
“Diode Test mode” is a DMM mode used to test diode function.
Answer 1: TRUE
Answer 2: FALSE
TRUE
DMM Advanced Feature Applications
“Capacitance Measurement mode” is a DMM mode used to measure capacitance or test resistance.
Answer 1: TRUE
Answer 2: FALSE
FALSE
DMM Advanced Feature Applications
“Duty Cycle mode (duty factor)” is an alternative frequency counter mode that measures the _____ a circuit is ON or OFF during a specified period of time.
Answer 1: number of hours
Answer 2: amount of time
Answer 3: percentage of time
Answer 4: number of minutes
percentage of time
DMM Advanced Feature Applications
An “AC sine wave” is a symmetrical waveform that contains _____.
Answer 1: 90 degrees
Answer 2: 180 degrees
Answer 3: 270 degrees
Answer 4: 360 degrees
360 degrees
AC Voltage
The “_____” of a sine wave is the maximum value of either the positive or negative alternation.
Answer 1: peak voltage value (Vmax)
Answer 2: peak-to-peak voltage value (Vp-p)
Answer 3: average voltage value (Vavg)
Answer 4: root-mean-square voltage value (Vrms)
peak voltage value (Vmax)
AC Voltage Measurement
The “_____,” or effective value, of a sine is the voltage value that produces the same amount of heat in a pure resistive circuit as direct current of the same value.
Answer 1: peak voltage value (Vmax)
Answer 2: peak-to-peak voltage value (Vp-p)
Answer 3: average voltage value (Vavg)
Answer 4: root-mean-square voltage value (Vrms)
root-mean-square voltage value (Vrms)
AC Voltage Measurement
Alternating-current voltage measurement procedures may vary slightly with different DMMs.
Answer 1: TRUE
Answer 2: FALSE
TRUE
AC Voltage Measurement Procedures
To measure alternating-current voltages with a DMM, first set the function switch to DC voltage.
Answer 1: TRUE
Answer 2: FALSE
FALSE
AC Voltage Measurement Procedures
In general, all alternating-current voltage sources vary from fluctuation in direct-current voltage over power distribution systems.
Answer 1: TRUE
Answer 2: FALSE
FALSE
Voltage Measurement Analysis
A “decibel (dB)” is the measure of the strength of one _____ signal compared to another.
Answer 1: audible
Answer 2: electrical
Answer 3: electronic
Answer 4: visible
electronic
Voltage Measurement Analysis
A dB measurement requires first taking a measurement at the input and using the Relative (REL) mode to establish a stored reference value of _____ dB.
Answer 1: 0
Answer 2: 1
Answer 3: 10
Answer 4: 15
0
Voltage Measurement Analysis
