L3

Question 1

including multi-meter’s current ranges have a certain resistance with particular
current and voltage requirement at full scale detection.

Answer 1

Ammeter

Question 2

Multi-Meters inherently measure voltage, and pass a current to be measured through a shunt resistance, measuring the voltage developed across it.

Answer 2

Ammeter

Question 3

The voltage drop is known as the “_____ _____,” specified in volts per ampere.

Answer 3

Burden voltage

Question 4

It is an error/effect when the ammeter is inserted in the circuit of interest.

Answer 4

Burden voltage

Question 5

can be significant in very low-voltage and low current circuit areas.

Answer 5

Burden voltage

Question 6

Analog or deflection types are un-buffered, and draw current from the circuit
under test to deflect the meter pointer.

Answer 6

Voltmeter

Question 7

The impedance of the meter varies depending on the basic sensitivity of the meter movement and the range which is selected.

Answer 7

Voltmeter

Question 8

may not change in different ranges but this becomes significant when lower current range is selected.

Answer 8

Voltage drop

Question 9

becomes additional load to the circuit being measured.

Answer 9

Voltmeter

Question 10

The history of the basic meter movement used in direct current measurement can be trace back to

Answer 10

Hans Oersted’s discovery in 1820

Question 11

What did Hans Oersted discovered in 1820

Answer 11

The relationship of Current and magnestism

Question 12

Who discovered the relationship between current and magnetism

Answer 12

Hans Oersted

Question 13

When did the relationship between current and magnetism discovered

Answer 13

1820

Question 14

How many years did various types of devises that made used of the Oersted’s discovery were developed?

Answer 14

The next half of a century

Question 15

one of the instruments for measuring electrical current par excellence.

Answer 15

Galvonometer

Question 16

This device is used on electrical circuits to know and measure the intensity and direction of electrical current.

Answer 16

Galvonometer

Question 17

Who discovered galvonometer

Answer 17

Luigi Galvani

Question 18

When did Jacques D’Arsonval patented a moving coil galvanometer?

Answer 18

1881

Question 19

What did Jacques D’Arsonval do in 1881

Answer 19

patented a moving coil galvanometer

Question 20

Who patented a moving coil galvonometer in 1881?

Answer 20

Jacques D’Arsonval

Question 21

is generally used for direct current measurement application.

Answer 21

D’Arsonval Meter Movement

Question 22

What are other meter movement developed ?

Answer 22

Electrodynamometer movement and the Iron Vane meter movement.

Question 23

What is the general application of iron vane meter movement and electrodynamometer

Answer 23

Alternating current measurement
AC measurement

Question 24

Its general application is to measure ac.

Answer 24

Iron vane meter movement & electrodynamometer

Question 25

The basic moving coil system is known as

Answer 25

D'Arsonval meter movement/ PMMC-Permanent Magnet Moving Coil Meter Movement

Question 26

is generally set in a jewel and pivot suspension system to reduce friction.

Answer 26

Moving coil mechanism

Question 27

Another method that provides a more sensitive but more expensive meter movement

Answer 27

Taut Band suspension system

Question 28

a typical full scale current for a Jewel and Pivot suspension system is

Answer 28

5 micro A

Question 29

a full scale current for Taut Band suspension system is ? entirely practical

Answer 29

2 micro A

Question 30

The typical commercial D’Arsonval Meter Movement operates on the principle of

Answer 30

DC motor

Question 31

is a current responding device.

Answer 31

D'Arsonval meter movement

Question 32

Current through coil causes it to behave as an _________ with its north and south poles.

Answer 32

Electromagnet

Question 33

is the most fundamental meter movement used today

Answer 33

Electrodynamometer movement

Question 34

is a current sensitive devise.

Answer 34

D'Arsonval meter movement & Electrodynamometer

Question 35

That is the pointer deflects ______ because of the current flow through the moving coil.

Answer 35

Upscale

Question 36

may be used to measure direct current or alternating current or voltage or single phase power in wattmeter.

Answer 36

Single coil meter movement

Question 37

may be used in Polly-phase wattmeter and the crossed coil meter movement may be used as power factor meter or as frequency meter.

Answer 37

Double coil meter movement

Question 38

electrodynamometer movement's most important applications are as

Answer 38

volt meter and ammeter standard and transfer instrument.

Question 39

Because of the inherent accuracy it is used as standard instrument for the calibration of other instruments.

Answer 39

Electrodynamometer

Question 40

is applied to an instrument that may be calibrated with DC source then used without modification to measure AC.

Answer 40

Transfer instrument

Question 41

This gave us direct means of equating AC and DC measurement of voltage and current with frequency limit of

Answer 41

0 - 125 Hz

Question 42

consist of a fixed coil divided into two equal halves separated by a movable coil

Answer 42

single coil Electro dynamometer Movement

Question 43

is capable of handling much more current than a D’Arsonval Meter Movement could handle without a shunt.

Answer 43

Electrodynamometer movement

Question 44

the most extensive application of the electrodynamometer movement is in

Answer 44

Wattmeter

Question 45

may be used for AC and DC power

Answer 45

Wattmeter

Question 46

is consisting of a fixed coil of many turns and two iron vanes placed inside the fixed coil.

Answer 46

Iron Vane Meter Movement

Question 47

It is widely used in industry for application in which ruggedness is more important than a high degree of accuracy.

Answer 47

Iron vane meter movement

Question 48

The same square law meter scale used in

Answer 48

Electrodynamometer Movement is used in Iron Vane Meter Movement.

Question 49

The moving vane instruments are rarely used for measuring direct current except for very inexpensive indicators such as charge and discharge indicators on automobiles.

Answer 49

Iron vane meter movement

Question 50

are used extensively in industry for measuring alternating current, when 5% to 10% error is acceptable

Answer 50

Iron vane meter movement

Question 51

It can be used for current and voltage measurements but it is very sensitive to frequency change.

Answer 51

Iron vane meter movement

Question 52

This meter movement is sensitive to frequency primarily because magnetization of the iron vane is nonlinear and because of losses incurred by eddy current and hysteresis.

Answer 52

Iron vane meter movement

Question 53

can change depending on the current range selected, since different ranges usually use different values of shunt resistance.

Answer 53

Percent of error/effect

Question 54

To check for its effect on accuracy and on external circuit operation the meter can be switched to different ranges; the current reading should be the same and circuit operation should not be affected if

Answer 54

Burden voltage is not a problem

Question 55

If this voltage is significant it can be reduced (also reducing the inherent accuracy and precision of the measurement) by

Answer 55

Using higher current ranges

Question 56

To measure voltage, connect the voltmeter in parallel with the

Answer 56

Load and source of interest

Question 57

( volt meter )This voltage drop is known as

Answer 57

Loading error/ effect

Question 58

The moving coil mechanism is generally set in a

Answer 58

Jewel and pivot suspension system

Question 59

is a horseshoe shaped permanent magnet with soft iron pole pieces attached to its north and south poles.

Answer 59

D'Arsonval meter movement

Question 60

Because of the inherent accuracy it is used as standard instrument for the calibration of other instruments.

Answer 60

Electrodynamometer

Question 61

Current from the circuit being measured passes through all the coils causing a _______ around the fixed coil.

Answer 61

Magnetic field

Question 62

Since it has higher current handling capabilities due to its design it became less sensitive

Answer 62

Electrodynamometer

Question 63

The electrodynamometer sensitivity is approximately about

Answer 63

20 to 100/V.

Question 64

The electrodynamometer sensitivity is approximately about

Answer 64

20 to 100/V.