C4 LT1

Question 1

How do digital multimeters measure the waveforms under test?

Answer 1

True RMS or average responding methods

Question 2

What are digital voltmeters commonly used for?

Answer 2

Voltage measurements

Question 3

What is a DC voltage source?

Answer 3

Unidirectional current flow

Question 4

What is the purpose of a diode?

Answer 4

Allows current to flow in one direction only

Question 5

In what configuration is the meter placed with the device being measured?

Answer 5

In parallel

Question 6

How is DC voltage usually supplied?

Answer 6

From a battery or power supply

Question 7

What voltage is approximately for most silicon diodes?

Answer 7

0.7volts

Question 8

What does a digital multimeter with autoranging feature do?

Answer 8

Automatically select the best accuracy and resolution range

Question 9

What creates AC voltage?

Answer 9

An Alternator at a hydroelectric plant

Question 10

What is a rectifier used for?

Answer 10

Convert AC to DC

Question 11

What does the continuity function of a DMM do ?

Answer 11

Verifys circuit completion

Question 12

How can the autorange feature on a DMM be changed to manual range?

Answer 12

Using the range button

Question 13

What is the AC voltage function used for?

Answer 13

Measuring changing voltage

Question 14

How can DC voltage be produced?

Answer 14

Electromagnetism, chemicals, heat, solar panels

Question 15

How can the current be measured with a standard DMM?

Answer 15

Interrupt circuit, connect in series

Question 16

What does the function control switch on a digital multimeter do?

Answer 16

Selects the electrical quantity to be measured

Question 17

What can a DMM set for the DC voltage function be used to test?

Answer 17

Battery banks, DC motors, DC generators

Question 18

What type of current can clamp-on ammeters measure?

Answer 18

Alternating current

Question 19

What is the difference between true RMS and average responding meters?

Answer 19

Integration circuit vs. simple circuit

Question 20

What is the typical input impedance of most digital meters?

Answer 20

10 megohms

Question 21

What does a digital ammeter measure?

Answer 21

Current in an electrical circuit

Question 22

What is the relationship between induced voltage and the strength of the magnetic field?

Answer 22

Proportional

Question 23

How can you determine if a DMM is a true RMS meter?

Answer 23

Check the manufacturer’s specifications

Question 24

Why does a voltmeter with low resistance compared to the circuit give a false reading?

Answer 24

Changes the circuit by lowering resistance

Question 25

What causes current to flow through a circuit?

Answer 25

Power source connected to a device

Question 26

What can a clamp-on meter measure?

Answer 26

AC and DC voltages, resistance

Question 27

What is the term for the effect a meter has on the circuit by increasing current flow?

Answer 27

Meter loading

Question 28

What is current?

Answer 28

Flow of electrons when voltage is applied

Question 29

What are the different types of alternators?

Answer 29

Steam-powered and wind-powered

Question 30

What is current measured in?

Answer 30

Amperes or amps

Question 31

What does AC voltage do?

Answer 31

Changes in magnitude and polarity

Question 32

What can most DMMs measure in terms of current?

Answer 32

Micro-amp range to 10 amps

Question 33

Are clamp-on current probe accessories available for both AC and DC currents?

Answer 33

Yes

Question 34

What is the voltage produced by a DMM in diode test mode?

Answer 34

2.5 volts

Question 35

What can the continuity function be used for in troubleshooting?

Answer 35

Test components like fuses and switches

Question 36

How does a DMM indicate continuity?

Answer 36

Audible signal or tone

Question 37

What is the maximum current measurement for most DMMs?

Answer 37

10 amperes

Question 38

What will the display indicate on a DMM when the measurement value exceeds the selected range?

Answer 38

OL (overload)

Question 39

What does a true RMS meter use to compute the RMS value of the waveform under test?

Answer 39

Integrated circuit

Question 40

What type of circuits require a true RMS DMM for accurate measurement?

Answer 40

Lighting circuits with electronic ballasts, circuits with variable-speed drives, and computers

Question 41

What does input impedance limit when taking measurements with a meter?

Answer 41

Current drawn by the meter

Question 42

What effect can occur if a voltmeter has a resistance that is too low in comparison to the circuit?

Answer 42

False reading due to meter loading

Question 43

Why are current measurements taken?

Answer 43

To ensure circuit is not overloaded

Question 44

How do clamp-on meters measure current?

Answer 44

Current transformer

Question 45

Where is the AC voltage function commonly used?

Answer 45

Testing and troubleshooting AC circuits

Question 46

What are the types of digital ammeters?

Answer 46

Panel mount, bench, clamp types, DMMs

Question 47

Where is the core material of the current transformer located?

Answer 47

Jaw of the meter

Question 48

What are clamp-on current probe accessories used for?

Answer 48

Measure higher current values and safely take current readings without opening a circuit.

Question 49

What induces voltage in the current transformer?

Answer 49

Changing magnetic field

Question 50

How do clamp-on ammeters measure current?

Answer 50

Hall effect generator principle