Deck 17: Electrical Measuring Instruments Another Application of Electromagnetism

Question 1

Many digital meters have voltage range settings from 20 millivolts to 200 volts, and the higher ranges are used for accuracy.

Answer 1

False

Question 2

To use an ohmmeter, the tips of the test leads are first held together (short circuited) and the rheostat (variable resistor) is adjusted so that the meter pointer moves to the ____ of the scale and points to the 0 ohms mark.

A)left-hand end
B)middle
C)right-hand end
D)bottom

Answer 2

C

Question 3

A simple galvanometer, by itself, has a very limited use; the most useful galvanometers are scaled as macroammeters.

Answer 3

False

Question 4

A ____ has a tapered jaw that can be opened and closed single-handedly by pressure action on a side lever.

A)clamp-on accessory
B)meter reader
C)connecting reader
D)clamp meter

Question 5

Meter manufacturers generally make meter shunts of a material called manganin (a copper-nickel-manganese alloy) rather than copper.

Question 6

To measure the wattage of a circuit, a meter must have two coils; one coil is affected by the magnetism and one by the resistance.

Question 7

A voltmeter is obtained by connecting a high resistance in series with the galvanometer, and these voltage-dropping, series-connected resistors are known as ____.

A)Aryton shunts
B)additions
C)multipliers
D)droppers

Question 8

Most digital meters have an input impedance of about ____ megohms on all ranges.

A)10
B)30
C)35
D)50

Question 9

To measure large currents with the galvanometer, a known large fraction of a large current is bypassed through a parallel low resistor called a ____.

A)tunnel
B)shoot
C)connection cable
D)shunt

Question 10

Ammeters, voltmeters, and ohmmeters are all similar in construction and are modifications of a basic instrument called a(n) ____.

A)galvanometer
B)magnetometer
C)polarized meter
D)analog meter

Question 11

Digital ohmmeters measure resistance by measuring the amount of voltage drop across an unknown resistance.

Question 12

Analog meters change scale value by inserting or removing ____ from the meter circuit.

A)volts
B)amps
C)resistance
D)power

Question 13

The ____ contains a high-voltage generator that supplies current through the series resistors and the unknown resistance (R) to the two-coil assembly that operates the pointer.

A)megohmmeter
B)macrohmmeter
C)millohmmeter
D)kilohmmeter

Question 14

The quality of a voltmeter is indicated by its conductivity, that is to say, by the amount of current required to force the pointer to the end of the scale (full-scale deflection.).

Question 15

Wattmeters that contain both stationary and moving coils are generally referred to as ____ wattmeters.

A)stable
B)dynamic
C)flexible
D)variable

Question 16

A(n) ____ measures voltage, but it does not contain a meter movement or digital display.

A)voltage tester
B)ohm-tester
C)voltage meter
D)ohmmeter

Question 17

An ohmmeter must never be connected to a circuit when the power is turned on.

Question 18

One of the most common methods used to accurately measure values of resistance, inductance, and capacitance is with a bridge constructed by connecting four components together to form a parallel-series circuit.

Question 19

To measure very low resistance values, a volt-ohmmeter is used.

Question 20

Instruments used for measuring electrical quantities are generally classified as analog or digital meters.