Digital Multimeter Units 6-9

Question 1

“DC voltage” is voltage that flows in _____ direction(s) only.

Answer 1: one
Answer 2: two
Answer 3: three
Answer 4: four

Answer 1

one

DC Voltage

Question 2

The primary difference between alternating-current voltage and direct-current voltage is the _____.

Answer 1: shape of the sine wave
Answer 2: voltage source
Answer 3: amount of voltage drop on the circuits
Answer 4: voltage of the circuits

Answer 2

voltage source

DC Voltage

Question 3

Direct-current voltages exceeding _____ are used in specialized applications such as small electric railway systems and large railway systems.

Answer 1: 90V
Answer 2: 110V
Answer 3: 125V
Answer 4: 180V

Answer 3

180V

DC Voltage

Question 4

If DMM test leads do not match the polarity of the direct-current voltage point being tested, a(n) _____ sign appears to the left of the direct-current voltage measurement displayed.

Answer 1: negative
Answer 2: positive
Answer 3: equal
Answer 4: infinity

Answer 4

negative

DC Voltage

Question 5

Direct-current voltage is measured with a DMM using standard procedures, the first of which is to set the function switch to AC voltage.

Answer 1: TRUE
Answer 2: FALSE

Answer 5

FALSE

DC Voltage Measurement Procedures

Question 6

Unlike alternating-current voltages that can generally vary between -10% and +5% of the power source rating without causing any problems, even small direct-current _____ variations may indicate a problem.

Answer 1: amperage
Answer 2: voltage
Answer 3: a and b
Answer 4: none of these

Answer 6

voltage

Voltage Measurement Analysis

Question 7

The exact amount of acceptable direct-current voltage variation depends upon the _____.

Answer 1: DMM being used
Answer 2: circuit
Answer 3: application
Answer 4: amperage of the circuit

Answer 7

application

Voltage Measurement Analysis

Question 8

In some applications, direct-current voltage measurements may be taken in circuits that include alternating-current voltage.

Answer 1: TRUE
Answer 2: FALSE

Answer 8

TRUE

Voltage Measurement Analysis

Question 9

On most DMMs, the resistance mode shares the function switch position with another DMM mode.

Answer 1: TRUE
Answer 2: FALSE

Answer 9

TRUE

Resistance

Question 10

A DMM in resistance mode automatically begins to take a(n) _____ measurement, even before the test leads are connected to the component to be tested.

Answer 1: alternating-current
Answer 2: direct-current
Answer 3: resistance
Answer 4: continuity

Answer 10

resistance

Resistance

Question 11

A DMM measures resistance with the _____ de-energized.

Answer 1: DMM
Answer 2: circuit
Answer 3: component
Answer 4: b or c

Answer 11

b or c

Resistance Measurement Procedures

Question 12

The resistance measurement displayed by the DMM is the total resistance through all possible paths between the ______.

Answer 1: panel and the receptacle
Answer 2: test leads
Answer 3: voltage source and the DMM
Answer 4: none of these

Answer 12

test leads

Resistance Measurement Procedures

Question 13

The resistance of all components connected in _____ with the component tested affects (usually lowers) the resistance reading.

Answer 1: series
Answer 2: parallel
Answer 3: series-parallel
Answer 4: any of these

Answer 13

parallel

Resistance Measurement Procedures

Question 14

An open switch has continuity.

Answer 1: TRUE
Answer 2: FALSE

Answer 14

FALSE

Continuity

Question 15

The main advantage of using the continuity test mode is that a(n) _____ response is sometimes more desirable than reading a resistance measurement.

Answer 1: audible
Answer 2: visible
Answer 3: vibrating
Answer 4: all of these

Answer 15

audible

Continuity

Question 16

When testing for _____, the DMM beeps based on the resistance of the component under test.

Answer 1: resistance
Answer 2: capacitance
Answer 3: continuity
Answer 4: all of these

Answer 16

continuity

Continuity

Question 17

“Current” is the amount of _____ flowing through an electrical circuit.

Answer 1: atoms
Answer 2: electrons
Answer 3: neutrons
Answer 4: protons

Answer 17

electrons

Current

Question 18

An “ampere” is the number of electrons passing a given point in _____ second(s).

Answer 1: one
Answer 2: two
Answer 3: three
Answer 4: four

Answer 18

one

Current

Question 19

A “clamp-on ammeter” is a meter that measures _____ in a circuit by measuring the strength of the magnetic field around a single conductor.

Answer 1: voltage
Answer 2: amperes
Answer 3: current
Answer 4: all of these

Answer 19

current

Current Measurement Procedures

Question 20

The advantage of a clamp-on ammeter or a DMM with a clamp-on current probe accessory is that readings can be taken more _____ without opening or interrupting the circuit.

Answer 1: accurately
Answer 2: quickly
Answer 3: effectively
Answer 4: safely

Answer 20

safely

Current Measurement Procedures

Question 21

Both clamp-on ammeters and DMMs with a clamp-on current probe accessory are commonly used to measure currents from _____.

Answer 1: 0.25A (or less) to 1,000A
Answer 2: 0.50A (or less) to 2,000A
Answer 3: 1.00A (or less) to 3,000A
Answer 4: 1.25A (or less) to 4,000A

Answer 21

1.00A (or less) to 3,000A

Current Measurement Procedures

Question 22

Most DMMs have fuses that become part of the current-measuring _____.

Answer 1: function
Answer 2: test
Answer 3: circuit
Answer 4: none of these

Answer 22

circuit

Testing DMM Fuses

Question 23

When using clamp-on ammeters, separate conductors under test from other surrounding conductors by a few _____ whenever possible.

Answer 1: inches
Answer 2: feet
Answer 3: yards
Answer 4: miles

Answer 23

inches

Clamp-On Ammeter Measurement Procedures

Question 24

Care is required to protect the _____ when measuring alternating current or direct current with an in-line ammeter.

Answer 1: user
Answer 2: circuit
Answer 3: ammeter
Answer 4: all of these

Answer 24

all of these

In-Line Current Measurement Procedures

Question 25

“Ohm’s law” is the relationship between voltage (E), current (I), and resistance(R) in a _____.

Answer 1: conductor
Answer 2: raceway
Answer 3: circuit
Answer 4: all of these

Answer 25

circuit

Ohm’s Law

Question 26

Ohm’s law can be used for determining voltage, current, or resistance requirements _____.

Answer 1: during circuit design
Answer 2: for predicting circuit characteristics before power is applied
Answer 3: when using an in-line ammeter
Answer 4: a and b

Answer 26

a and b

Using Ohm’s Law

Question 27

In troubleshooting applications, Ohm’s law can be used to determine how a circuit should operate and how it is operating under _____.

Answer 1: power
Answer 2: ideal conditions
Answer 3: testing scenarios
Answer 4: maximum use

Answer 27

power

Using Ohm’s Law

Question 28

“Cold resistance” is the _____ of a component when operating current is not passing through the device.

Answer 1: continuity
Answer 2: resistance
Answer 3: capacitance
Answer 4: all of these

Answer 28

resistance

Using Ohm’s Law

Question 29

_____ is the relationship between power (P), voltage (E), and current (I) in an electrical circuit.

Answer 1: Ohm’s law
Answer 2: The “power formula”
Answer 3: Kirchoff’s law
Answer 4: none of these

Answer 29

The “power formula”

Power Formula

Question 30

The power formula is useful for determining expected current values because most electrical equipment lists a _____.

Answer 1: power rating
Answer 2: voltage
Answer 3: a and b
Answer 4: none of these

Answer 30

a and b

Using the Power Formula

Question 31

Ohm’s law and the power formula are limited to circuits in which electrical continuity is the only significant opposition to the flow of current.

Answer 1: TRUE
Answer 2: FALSE

Answer 31

FALSE

Ohm’s Law and Impedance

Question 32

“_____"”is the property of a circuit that causes it to oppose a change in current due to energy stored in a magnetic field.

Answer 1: Resistance (R)
Answer 2: Inductance (L)
Answer 3: Capacitance (C)
Answer 4: Impedance (Z)

Answer 32

Inductance (L)

Ohm’s Law and Impedance