Deck 8: Measuring Instruments

Question 1

The ____, unlike the voltmeter, is a very low-impedance device.

A) ammeter
B) ohmmeter
C) wattmeter

Answer 1

A

Question 2

Digital meters that do not contain a range setting control are known as ____ meters.

A) single range
B) manual
C) standard
D) autoranging

Answer 2

D

Question 3

An ammeter is used to measure current and must be connected in ____ with the load.

A) parallel
B) series
C) either a or b

Answer 3

B

Question 4

The test instrument used to measure current in an electrical circuit is called a(n) ____________________.

Question 5

____________________ meters are characterized by the use of a pointer and scales to indicate values.

Question 6

A(n) ____________________ is used to measure power in an electrical circuit.

Question 7

When the selector switch of a meter is turned to a new scale, steps of ____ are inserted in the circuit to increase the range or are removed from the circuit to decrease the range.

A) amperage
B) resistance
C) voltage
D) wattage

Question 8

The test instrument used to measure the resistance of an electrical circuit is called a(n) ____________________.

Question 9

The input impedance used to limit the flow of current through digital meters is accomplished by using ____.

A) field effect transistors
B) toroid current transformers
C) ammeter shunts
D) none of the above

Question 10

A voltmeter is designed to be connected in ____ with the circuit to be measured.

A) parallel
B) series
C) either a or b

Question 11

A(n) ____ must never be connected to a circuit when the power is turned on.

A) ammeter
B) ohmmeter
C) voltmeter
D) wattmeter

Question 12

The ____ must provide its own source of power.

A) ammeter
B) ohmmeter
C) voltmeter
D) wattmeter

Question 13

If a clamp-on ammeter is clamped around more than one power line of a 240 V circuit, the meter will read ____ volts.

A) 0
B) 120
C) 240
D) 480

Question 14

Any number can be multiplied by ____________________ by moving the decimal point one place to the right, and any number can be divided by ____________________ by moving the decimal point one place to the left.

Question 15

A(n) ____ is a low-resistance device used to conduct most of the circuit current away from the meter movement.

A) voltage shunt
B) ammeter shunt
C) wattage shunt
D) voltage rectifier

Question 16

When a toroid current transformer is used to measure AC current, the main power line acts as the ____ and is considered to be one turn.

A) secondary winding
B) primary winding
C) hollow core frame
D) AC rectifier

Question 17

The test instrument used to measure voltage in a circuit is called a(n) ____________________.

Question 18

The ____ is used to measure resistance.

A) ammeter
B) ohmmeter
C) voltmeter
D) wattmeter

Question 19

If a DC voltmeter is connected to an AC circuit with an applied voltage of 240 V, the meter will read ____ volts.

A) 120
B) 240
C) 480
D) 0

Question 20

AC/DC ammeters use the ____ effect as their basic principle of operation.

A) Smith
B) Jones
C) Hall
D) Oates

Question 21

Most AC ammeters use a ______________________________ to change scale values instead of shunts, which can be used to increase range but cannot be used to decrease range.

Question 22

When reading an ohmmeter scale, the value of resistance shown at the far left end of the scale is ____________________.

Question 23

A low-impedance voltage tester has a very large current draw compared with other types of voltmeters and should never be used to test ____________________-power circuits.

Question 24

A _________________________ is a device used to measure voltage, but does not contain a meter movement or a digital display.

Question 25

The ____________________ is the ratio of the number of turns of wire in the transformer primary winding to the number of turns of wire in the transformer secondary winding.

Question 26

When a large amount of AC current must be measured, current transformers known as ____________________, that have a standard secondary current rating of 5 A -- AC, are used.

Question 27

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

Question 28

When reading a digital meter, the symbol "mV" indicates ____________________.

Question 29

An ohmmeter should always be readjusted to ____________________ when the scale is changed.