Digital Multimeter Functions

Question 1

Witch DMM function is used to measure resistance

Answer 1

Ohmmeter

Question 2

Which DMM function is used to measure current flow in an electrical circuit ?

Answer 2

Ammeter

Question 3

What is the impedance value or most digital voltmeters

Answer 3

10 megohms

Question 4

Which meters are more commonly used in electrical trade

Answer 4

Digital

Question 5

Which meters are more accurate analog or digital

Answer 5

Digital

Question 6

What is the abbreviation DMM short for

Answer 6

Digital multimeter

Question 7

Which meter is used to take current measurements without opening the circuit

Answer 7

Clamp on ammeters

Question 8

What is meter loading

Answer 8

The effect a meter has on a circuit

(Due to the meter changing the circuit by lowering the total resistance)

Witch lowers the voltage to

Question 9

When working with electronic ballast, VSD or computer what do you use (true RMS) or (average responding DDM?)

Answer 9

You use true RMS because these items have non sinusoidal wave forms

Question 10

Witch DMM setting would be used to measure the out put of an
Alternator_______
Rectifier_________

Answer 10

Alternator = AC volts
Rectifier = DC volts

Question 11

List to advantage of a clamp on ammiter
Over a DMM

Answer 11

They have a higher amperage rating
You don’t have to open the circuit

Question 12

Witch meter function would be selected to provide quick and easy testing of weather a fuse is open or has a complete path through it

Answer 12

Continuity

Question 13

DMM amperage rating is what

Answer 13

10 amps

Question 14

List three causes of insulation deterioration

Answer 14

1, Mechanical damage
2, Heat
3, Oil

Question 15

List two applications where maggers are used

Answer 15

Routine checks
Checking wires in conduit

Question 16

List three types of electrical equipment that could have their insulation resistance tested

Answer 16

1, cables
2, motors
3, transformers

Question 17

What should always be done with a conductor before and after megger testing the conductor

Answer 17

1, Turn off power
2, discharge

Question 18

What is the minimum reading expected when meggering a motor conductor

Answer 18

1 megohm or higher

Question 19

What CSA standard covers workplace electrical safety

Answer 19

CSA standard Z462-08

Question 20

What category of DMM is required for testing where fault current are very high

Answer 20

Category IV

Question 21

The category rating of Test leads of a DMM must meet or exceeded the category rating of the DMM

True or false

Answer 21

True

Question 22

What must be done before using a DMM

Answer 22

Test on a known circuit to ensure that the DMM is working properly 

Question 23

Once you are finished using a DMM, you can throw it in to your toolbox
True or false

Answer 23

False

Question 24

Metre tests leads can be replaced with the cheapest leads available
True or false

Answer 24

False

Question 25

If a metre fuse is blown, it can be replaced with any fuse True or false

Answer 25

False

Question 26

Ideal metres must be stored in a dark room True or false

Answer 26

False Must be in a tempture controlled area

Question 27

What is the window on the DMM called where the reading appears

Answer 27

Display

Question 28

The bar graph has a polarity indicator on the left True or false

Answer 28

True

Question 29

Identify one cause of false readings on a DMM on a de energize circuit

Answer 29

Capacitive coupling

Question 30

False readings are normally none as

Answer 30

Ghost or stray voltage

Question 31

What must be done to get an accurate rating of OL appears on a display when the DMM is on manual range

Answer 31

Switch to a higher range

Question 32

The bar graph on a DMM reacts like the needle on an analogue metre True or false

Answer 32

True

Question 33

How does an analog meter work

Answer 33

It draws current from the circuit being measured to deflect the coil and pointer of the meter movement. The amount of current drawn dippends on the ohms per volt of the meter

Question 34

How do digital meters work

Answer 34

They use an analogy / to / digital converter to display a reading

Question 35

Which feature on a DMM would best be used to detect rapidly changing signal such as contact contact or micro switch

Answer 35

Bar graph