302 Introduction to grounding and bonding Flashcards by Blake Jessop

The human body is a good conductor because it is mostly salt water.

a. True
b. False

a. True

How well did you know this?

Not at all

Perfectly

The symbol used for impedance in an electrical formula is ____.

a. I
b. R
c. Z
d. Ohm’s sign
e. X

c. Z

How well did you know this?

Not at all

Perfectly

Potential difference refers to which of the following?

a. voltage
b. Resistance
c. Shock hazard of AC circuits as compared to DC circuits
d. Shock hazard associated with different grounding methods

a. Voltage

How well did you know this?

Not at all

Perfectly

O’Reilly’s first rule of electrical installations is to make them _____.

a. Work
b. Safe

b. Safe

How well did you know this?

Not at all

Perfectly

Electrical fault cause all of the following types of stresses, except ______.

a. Thermal
b. Seismic
c. Magnetic

b. Seismic

How well did you know this?

Not at all

Perfectly

Potential difference is a value measured in Ohm’s.

a. True
b. False

b. False

How well did you know this?

Not at all

Perfectly

Total opposition to current flow in an alternating current (AC) circuit is _____.

a. Impedance
b. Reactance
c. Resistance
d. None of these

a. Impedance

How well did you know this?

Not at all

Perfectly

The point of division Of a line and load is located in the ______.

a. Load side of the meter base
b. Customer side of the service head
c. Service point
d. Overcurrent devices in the service disconnect means

d. Overcurrent devices in the service disconnecting means

How well did you know this?

Not at all

Perfectly

A(n) _____ Conductor carries circuit current in normal operation.

a. Equipment grounding
b. Neutral
c. Grounding electrode
d. None of these

b. Neutral

How well did you know this?

Not at all

Perfectly

If the resistance of the body is 100 ohms, how much current would pass through the body when connected to a 120 Volt circuit?

a. 12 A
b. 10 mA
c. 10 Amps
d. 1.2 amps

d. 1.2 amps

How well did you know this?

Not at all

Perfectly

If a fault occurs at point III In figure 301.01, It is on the ______ side of the service.

a. Line
b. Load

b. Load

How well did you know this?

Not at all

Perfectly

If a fault occurs at point IV In figure 301.01, it is on the ____ Side of the service.

a. Line
b. Load

b. Load

How well did you know this?

Not at all

Perfectly

Which of the following are considered to be current carrying conductors?

I. Neutral conductor. II. Ungrounded conductor. III. Grounding conductor

a. I & II only
b. II only
c. I & III only
d. II & III only
e. I only

a. I & II only

How well did you know this?

Not at all

Perfectly

When a piece of equipment is connected to ground, it meets the definition for ____.

a. Insulated
b. Guarded
c. Isolated
d. Grounded

d. Grounded

How well did you know this?

Not at all

Perfectly

If two points in a circuit have a voltage between them but are then bonded together with a conductive jumper (a wire for example), There is essentially no longer ____ between them.

a. A difference of potential
b. A voltage
c. Both a & b
d. Neither a nor b

c. Both a & b

How well did you know this?

Not at all

Perfectly

A solidly grounded system is one where one of the current-carrying conductors is intentionally connected to the Earth.

a. True
b. False

a. True

How well did you know this?

Not at all

Perfectly

Which of the following is not an example of a solidly grounded system?

a. 120/240-volt, three phase, four wire
b. 480 V, three phase, three wire
c. 120/240 V, single-phase, 3 wire
d. 120/208 V, three phase, four wire

b. 480 V, three phase, three wire

How well did you know this?

Not at all

Perfectly

Potential difference is a value measured in ____.

a. Amps
b. Ohms
c. Volts
d. Watts

c. Volts

How well did you know this?

Not at all

Perfectly

A five wire system consists of grounded, three phase system and includes one insulated ground and one insulated grounding conductor.

a. True
b. False

a. True

How well did you know this?

Not at all

Perfectly

A solidly grounded system is a system in which one of the circuit conductors is grounded. This conductor _____ carry Current during normal circuit operations.

a. Does not
b. Does

a. Does not

How well did you know this?

Not at all

Perfectly

The definition of an equipment grounding conductor in the NEC generally covers many different concepts and parts of a grounding system.

a. True
b. False

a. True

How well did you know this?

Not at all

Perfectly

In terms of grounding, the earth is considered to represent _____.

a. zero potential
b. Infinite impedance
c. A natural battery
d. Negative polarity

a. Zero potential

How well did you know this?

Not at all

Perfectly

Most common configuration for a grounded, three phase, AC distribution system is for wire, center grounded (also called “wye connected”). The code requirements for identification of a grounded conductor are provided in section _______.

a. 250.119
b. 200.6(A)

b. 200.6(A)

How well did you know this?

Not at all

Perfectly

The abbreviation or symbol used for the unit of measure for impedance is _____.

a. VA
b. Z
c. W
d. A
e. V

b. Z

How well did you know this?

Not at all

Perfectly

The sum of all three components of current opposition is referred to as ______. a. Reactance b. Impedance c. Resistance d. Capacitance e. Inductance

b. Impedance

A ground rod is the only grounding electrode at a service. If the GEC becomes loose when connected to the rod, the branch circuit breakers in the service panel will take _____ Amount of time to open if ground fault occurs when one of the branch circuits. a. The same b. A longer c. A shorter

a. The same

Impedance (Z) ______. I. Is the total opposition to current flow in a circuit II. Includes resistance a. I only b. II only c. Both I & II d. Neither I nor II

c. Both I & II

Inductive reactance is related to ______. a. Radio-frequency interference (RFI) b. Capacitance c. Magnetic field d. Ground currents

c. Magnetic field

Unlike opponents in the direct current (DC) Circuit, the components in an alternating current (AC) Circuit that affect current flow are resistance and _______. I. Inductive reactance. II. Capacitive reactance a. I only b. II only c. Both I and II d. Neither I nor II

c. Both I and II

When conductor temperature increases, the resistance of the conductor increase. This causes the ampacity of the conductor to decrease. a. True b. False

a. True

Reminders: Ampacity Corrections are required when conductors are installed in a race way with too many current carrying conductors. Because of the proximity of the other conductors, additional currents are included which caused the conductor temperature to increase. Ampacity corrections are also required when conductors are installed in an area where the ambient Temperature is high. When conductor temperature increases, the resistance of the conductor increases. This causes the Ampacity of the conductor to _______. a. Decrease b. Stay the same c. Increase

a. Decrease

When current passes through a conductor, a magnetic field is created around the conductor. When individual current conductors are either in close proximity (In wire Ways, trenches, cable trays, etc.) or Contained in the same cable or conduit, the magnetic fields Cancel each other because the current In each conductor are not in phase with each other. a. True b. False

a. True

Which of the following is Measured in Ohm’s? I. Inductive reactance. II. Capacitive reactance. III. Counter-electromotive force a. I only b. III only c. I & II only d. I, II, & III e. I & III only

c. I & II only

Total opposition to the flow of electric current is called resistance in a direct current (DC) circuit and ______ In an alternating current (AC) circuit. a. Resistance b. Impedance c. Reactance d. None of these

b. Impedance

As circuit resistance _____, the time it takes for an OCPD to operate decreases. a. Increases b. Decreases

b. Decreases

How does grounding prevent an electrical fault? a. Grounding protects the “line side”of the circuit. b. Grounding protects the “load side” of the circuit. c. Grounding reduces potential difference. d. Grounding cannot prevent an electrical fault

d. Grounding cannot prevent an electrical fault

Each 480 V, three phase, wye-connected feeder disconnect with a minimum rating of _____ amperes Is required to be ground-fault protected. a. 600 b. 1500 c. 1200 d. 1000

d. 1000

A _____ is an electrical fault. I. Short circuit. II. Ground-fault a. I only b. II only c. Both I & II d. Neither I nor II

c. Both I and II

Circuits HA –1, -4, and -11 With a neutral and circuits HA-2, -3, and -5 With a second neutral I’ve been pulled in EMT from a 277/480 V, three phase, four wire paddleboard to fluorescent luminaires That have been installed in several classrooms in a school. If the wire from breaker 5 comes in contact with the wire from breaker 11, ____ will occur. a. A backfeed b. A ground fault c. A short circuit

a. A backfeed

Circuits HA-1, -4, -11 With a neutral have been pulled into EMT from a 277/480 V, three phase, four wire paddleboard to some high-bay luminaires that have been installed in a warehouse. If the wire from breaker 4 Come in contact with the neutral, ______ Will occur. a. A backfeed b. A short circuit c. A ground fault

b. A short circuit

Refer to figure 301.02. Sealtite (LFKC) is used between the switch and the motor. The insulation on the “hot” has been damaged and the copper is touching the motor terminal housing. How much current is “seen” by the circuit breaker? A separate grounding conductor was not installed in either raceway. The impedance of the sealtite is 50p ohms. a. 55 A b. 923 A c. 20 A d. 11.45 A e. 692.5 A

d. 11.45 A

All of the following are considered a short circuit, except for ______. a. Phase-to-neutral fault b. Phase-to-phase fault c. Neutral-to-ground fault d.line-to-line fault

c. Neutral-to-ground fault

An overload can be excessive current caused by a fault (short circuit or ground fault). a. True b. False

b. False

The rating of a branch circuit is determined by ______. a. Conductor size b. Whether the circuit is series or parallel c. Article 220 calculations d. Size of overcurrent protective device

d. Size of overcurrent protective device

And over current can be excessive current caused by a fault (short circuit or ground fault). a. True b. False

a. True

Circuits LA-1, -4, and -11 are Rated at 20 A and have a neutral. These have been run as, 4 wire, 12 AWG MC cable from a 120/208 V, three phase, four wire paddleboard do a junction box. Fluorescent luminaires has been installed in several offices in a Business and connected to these circuits. The offices will be used continuously during the business day. Each luminaire draws 1.2 A, if no more than ______ Luminaires are connected to circuit LA –4, the circuit breaker will operate within its ratings. a. 13 b. 15 c. 17 d. 16 e. 14

a. 13

Which of the following conditions would be classified as an overcurrent? I. A 36-A Non-continuous load connected to a 40-A fuse II. An underground conductor touching a ground conductor III. An underground Conductor touching a grounded metal enclosure a. I, II & III b. I & II only c. I only d. II only e. II & III only

e. II & III only

Which of the following conditions would be classified as an overload? I. 43-A Non-continuous load connected to a 40-A fuse II. An ungrounded conductor touching another underground conductor III. And ungrounded conductor touching the ground metal and closure a. I, II, & III b. I only c. II & III only d. II only I & III only

b. I only

Which of the following determines the severity of an electric shock? I. The path taken by current through the body II. The length of time current flows III. The amount of current flowing a. II & III only b. I & II only c. I & III only d. I, II, & III e., II only

d. I, II, & III

A 120-volt load is operating When you open the neutral in a J-box. If you touch the neutral from the load with your left hand and the ground metal conductor with your right hand, your body will be in _____ with the load. a. Series b. Parallel

a. Series

If _____ I have current flows through the human body, it can be fatal. a. 0.75 mA b. 2.5 mA c. 5 mA d. 200 mA

d. 200 mA

If you were to touch and energize undergrounded conductor and a grounded surface ______. I. The circuit breaker will trip. II. You will be shocked a. I only b. II only c. Both I & II d. Neither I Nor II

b. II only

A 1-phase load is is operating at 208 volts. If you were working on the energized equipment and touched one of the “hot” terminals with your left hand and the other hot with your right hand, how much current would flow through your body? Your body resistance is 5 kOhms, and the equipment has a Impedance equal to 23 ohms. a. 9.13 A b. 42 mA c. 22.9 A d. 35.4 A e. 24 mA

b. 42 mA

A 1-phase load is operating a 277 volts. If you were working on the energized equipment and touched one of the “hot” terminals with your left hand and the neutral with your right hand, how much current would flow through your body? Your body resistance is 5 kOhms and the equipment has a impedance equal to 23ohms. a. 12.1 A b. 12.04 A c. 55.4 mA d. 41.4 mA e. 22.9 A

c. 55.4 mA

If the resistance of the body is 100 ohms, how much current would pass through the body when connected to a 120-volt circuit? a. 10 mA b. 12 A c. 1.2 amps d. 10 amps

c. 1.2 amps

You should observe “no smoking” areas near any flammable materials. a. True b. False

a. True

Never carry heavy objects when climbing a ladder. a. True b. False

a. True

If your power tool has auxiliary handles, they must be used to keep the tool in your grip. a. True b. False

a. True

You should be aware of hazards created by other trades working near you. a. True b. False

a. True

Always place your ladder on a flat, stable surface and ____. a. Anchor it to the floor b. Observe the 3-point rule c. Have a co-worker hold it d. All of these

b. Observe the 3-point rule

Lock-out and verify before working on or near any electrical equipment. a. True b. False

a. True

Be sure the GFCI receptacles are in good working order and tested _____. a. Annually b. Weekly c. Regularly d. Daily

c. Regularly