Deck 12: Conductors and Insulators

Question 1

______________ fuses have coiled construction and are designed to open only on a continued overload.

Answer 1

Slow-blow

Question 2

The advantage of a circuit breaker is that it can be ______________ once the bimetallic strip cools down and the short circuit has been removed.

Answer 2

reset

Question 3

The resistance of a wire conductor is ______________ proportional to its cross-sectional area.

Answer 3

inversely

Question 4

Temperature ______________ states how much the resistance changes for a change in temperature.

Question 5

An ______________ is an atom, or group of atoms, that has a net electric charge, either positive or negative, resulting from a loss or gain of electrons.

Question 6

Liquids that are good conductors because of ionization are called ______________.

Question 7

Substances that have very high resistance, of the order of many megohms, are classed as ______________.

Question 8

To reduce the ______________ effect, conductors that have high voltage should be smooth, rounded, and thick.

Question 9

______________ of conductors, both wires and printed wiring, can be checked with an ohmmeter.

Question 10

Resistance of a wire is

A) inversely proportional to its length
B) directly proportional to its length
C) directly proportional to its cross-sectional area
D) not affected by the resistivity of the conductor

Question 11

What is the rating that lists the resistance of a metal having the standard wire size of a 1-ft length with a cross-sectional area of 1 cmil?

A) Power
B) Specific gravity
C) Specific resistance
D) Tolerance

Question 12

For applications in heating elements, what type wire should be used?

A) Copper
B) Silver
C) Tungsten
D) Aluminum

Question 13

What is the factor that states how much the resistance changes for a change in temperature?

A) Gain or b
B) Thermal
C) Temperature coefficient
D) Coefficient of coupling

Question 14

When R increases with an increase in temperature

A) it is faulty and should be replaced
B) it has a negative temperature coefficient
C) it has a positive temperature coefficient
D) the temperature should be adjusted

Question 15

A metal that does not change resistance when the temperature increases or decreases

A) has a positive temperature coefficient
B) has a negative temperature coefficient
C) should never be used to make precision wire-wound resistors
D) has a zero temperature coefficient

Question 16

What effect occurs when certain metals or ceramic materials are cooled down to very low temperatures to reduce its resistance?

A) Zero resistance
B) Negative temperature coefficient
C) Superconductivity
D) Positive temperature coefficient

Question 17

An atom, or group of atoms that has a net electric charge, either positive or negative, resulting from a loss or gain of electrons is a(n)

A) proton
B) joule
C) ion
D) ampere

Question 18

Liquids that are good conductors because of ionization are called

A) hydration
B) ionites
C) electrolytes
D) bionic solutions

Question 19

) Substances that have very high resistance, on the order of many megohms, are classed as

A) electrolytes
B) ions
C) conductors
D) insulators

Question 20

Insulators maintain a charge because electrons cannot flow to neutralize the charge and are commonly called

A) semi-conductor materials
B) ionic materials
C) dielectric materials
D) superconductive materials

Question 21

Which of the following is not an insulator?

A) Air
B) Wax
C) Aluminum
D) Mica

Question 22

What is a result of breakdown in the insulator because of a high potential difference that ruptures the dielectric?

A) Avalanche breakdown
B) Surge current
C) Spark discharge
D) Corona effect

Question 23

Continuity of wires and printed wiring can be tested by using a(n)

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

Question 24

The smaller the diameter of a wire

A) the less current it can carry
B) the more current it can carry
C) the IR drop will be lower
D) the cross-sectional area will be larger

Question 25

What prevents a wire conductor from coming into contact with any nearby conductor?

A) Cable ties
B) Wire insulation
C) Conductors
D) Ceramic posts

Question 26

Which of the following AWG wires has the largest cross-sectional area?

A) No. 12
B) No. 1
C) No. 00
D) No. 0000

Question 27

When two or more conductors are formed in a common covering, it is referred to as a

A) cable
B) coax
C) run
D) strand

Question 28

Which of the following cable connectors is universally used in cable television?

A) RCA-type
B) Phone plug
C) F connector
D) Multiple pin

Question 29

Most electronic circuits are mounted on a plastic or fiberglass insulating board with printed wiring that is called a

A) printed circuit board
B) breadboard
C) wiring panel
D) fiber board

Question 30

What size soldering iron should be used when soldering or desoldering?

A) 5 W
B) 25 W
C) 75 W
D) 100 W

Question 31

A component that allows us to control whether the current is on or off in a circuit is a

A) fuse
B) switch
C) conductor
D) potentiometer

Question 32

A device constructed of a thin bimetallic strip that expands with heat and in turn opens the circuit is called a

A) fuse
B) switch
C) circuit breaker
D) thermistor

Question 33

The smaller the diameter of a wire, the more current it can carry.

Question 34

For a given length of wire, the resistance, R, decreases as its diameter and cross-sectional area increase.

Question 35

The main function of a wire conductor is to connect a source of applied voltage to a load with minimum IR voltage drop in the conductors.

Question 36

A conductor is any material that resists or prevents the flow of electric charge, such as electrons.

Question 37

Examples of insulators include air, paper, plastics, rubber, mica, and glass, to name a few.

Question 38

In our homes, the higher power appliances operate from 240 V because at twice the voltage, only half the current is needed to obtain the required power.

Question 39

No. 000 gage wire has a larger cross-sectional area than No. 1 gage wire.

Question 40

The American Wire Gage numbers specify the size of round wire in terms of its diameter and cross-sectional area.

Question 41

In typical applications, hook-up wire for electronic circuits in the order of milliamperes is generally about No. 2.

Question 42

Most wire conductors are silver.

Question 43

Two or more conductors in a common covering form a cable.

Question 44

The RCA-type plug is universally used in cable television.

Question 45

When soldering or desoldering components mounted on a printed circuit board, use a small iron of about 25 W to 30 W rating.

Question 46

The resistance of a wire conductor is directly proportional to its length and inversely proportional to its cross-sectional area.

Question 47

Switches cannot have more than two poles and two throws.