Deck 5: Switches and Receptacles

Question 1

A 3-way switch has a common terminal to which the switch blade is always connected, and it has two other terminals called terminals.

A)mover
B)utility
C)traveler
D)mobile

Answer 1

C

Question 2

How are snap switches and metal faceplates grounded?

Answer 2

A metal box is considered adequately grounded provided the metal raceway, Type AC or Type
MC cable, is properly grounded at its origin, NEC 250.118.This being the case, the metal yoke
of the snap switch is considered grounded when secured to the metal box by metal screws.In turn, a metal faceplate is considered grounded when secured to the metal yoke of a snap switch.The effective ground-fault current path is a multistep situation: first the metal raceway or armor must
be grounded; then the metal outlet box must be grounded; then the yoke on the snap switch is grounded; and finally the metal faceplate is grounded by the No.6-32 metal screws that secure the faceplate to the switch.

Question 3

What is electrical noise, and what is its source?

Answer 3

"Electrical noise," as referred to when discussing electronic equipment, is any extraneous signal that tends to interfere with the signal normally present in or passing through a system.Induced noise might be EMI (electromagnetic interference) or RFI (radio frequency interference).It might be heard as a hum, buzzing, whining, or static.The cause might be traced to such things as an electric motor, ignition on a furnace, fluorescent and other types of electronic discharge luminaires, nearness to a power line, arc welders, power-supply switching circuits, cellular phones, other audio/video equipment, office electronic equipment, and nearness of computer cables to electric light and power wiring.These things are capable of creating unwanted waveforms that can scramble or distort digital signals.

Question 4

What is the difference between the acceptable impedance of a ground path for branch-circuit wiring and the acceptable impedance for electronic equipment?

Question 5

An ac-dc general­use snap switch is always marked with the .

A)resistance
B)year of manufacture
C)phrase "ac­dc switch"
D)current and voltage rating

Question 6

An ungrounded conductor is also known as a conductor.

A)hot
B)ground
C)neutral
D)positive

Question 7

To reduce "electrical noise" (electromagnetic interference), circuits with receptacle outlets that serve loads such as cash registers, computers, or other sensitive electronic equipment are often supplied by receptacles.

A)low-pass filtered
B)high-pass filtered
C)isolated ground
D)hospital-grade

Question 8

A switch is used where it is desired to control a light or group of lights, or other load, from one switching point.

A)three-way
B)single-pole
C)four-way
D)traveler

Question 9

Quality voltage provides a clean wave that is free from distortion.

A)triangle
B)sine
C)square
D)sawtooth

Question 10

How common are double-pole switches, and where are they used?

Question 11

When using cable for the wiring of 3-way switches, NEC 200.7(C)(1) permits the use of a conductor with insulation that is white or or has three continuous white stripes (not too common) as a switch supply only if the conductor is permanently reidentified by painting or other effective means.

A)black
B)red
C)green
D)gray

Question 12

In locations where severe abuse or heavy use is expected, receptacles are recommended.

A)electronic equipment
B)hospital-grade
C)isolated ground
D)locking plug

Question 13

Isolated ground receptacles are required by NEC 406.2(D) to have a(n) triangle on their face.

A)orange
B)green
C)blue
D)red

Question 14

Most electricians refer to switches as "toggle switches" or "wall switches."

A)snap
B)pressure
C)float
D)general

Question 15

An acceptable impedance for the grounding path associated with normal equipment grounding for branch-circuit wiring is ohms.

A)1 to 2
B)3 to 4
C)5 to 6
D)7 to 8

Question 16

When the wiring method is cable, you are stuck with the conductor insulation colors typically provided by the manufacturer.For three conductor cable, this will typically be black, white, and .

A)red
B)blue
C)green
D)orange

Question 17

The differences in plugs and receptacles are based on the and voltage rating of the device.

A)resistance
B)conductance
C)geometry
D)ampacity

Question 18

How do you prevent neutral conductors from overheating?

Question 19

The cover that is placed on a recessed box containing a receptacle or a switch is called a .

A)groundplate
B)faceplate
C)raised cover
D)double-pole

Question 20

In commercial buildings, protection is required for all 125-volt, single-phase, 15- and 20-ampere receptacles installed in bathrooms, in kitchens, on rooftops, outdoors, within 6 ft (1.8 m) from the outside edge of any sink, in indoor wet locations, in locker rooms with adjacent shower facilities, and in garages, bays, and similar areas.

A)NEC
B)EWC
C)GFCI
D)HOT