Podcast
Questions and Answers
What is the most important rule of electrical safety?
What is the most important rule of electrical safety?
Think first
Why should a person work with only one hand when possible?
Why should a person work with only one hand when possible?
So a current doesn't pass through your heart.
What range of electric current generally causes death?
What range of electric current generally causes death?
100 to 200 milliamperes
What is fibrillation of the heart?
What is fibrillation of the heart?
What is the operating principle of a defibrillator?
What is the operating principle of a defibrillator?
Who is responsible for enforcing OSHA regulations?
Who is responsible for enforcing OSHA regulations?
What is the mission of OSHA?
What is the mission of OSHA?
What is MSDS?
What is MSDS?
Who should have the key to a padlock used to lock out a piece of equipment?
Who should have the key to a padlock used to lock out a piece of equipment?
What is a ground fault?
What is a ground fault?
What is the approximate current at which a ground-fault detector will open a circuit?
What is the approximate current at which a ground-fault detector will open a circuit?
Name three devices used to provide ground-fault protection.
Name three devices used to provide ground-fault protection.
What are the 4 classes of fires?
What are the 4 classes of fires?
Which section covers grounding?
Which section covers grounding?
Definition of accessible?
Definition of accessible?
Define a bonding jumper.
Define a bonding jumper.
What is a generic term for a group of nonflammable synthetic chlorinated hydrocarbons used as electrical insulating media?
What is a generic term for a group of nonflammable synthetic chlorinated hydrocarbons used as electrical insulating media?
At no point along the floor line, in any wall space, can you be more than ____ ft from a receptacle outlet.
At no point along the floor line, in any wall space, can you be more than ____ ft from a receptacle outlet.
To accomplish this requirement, floor receptacle outlets satisfying this rule shall be located not more than ____ inches from the wall.
To accomplish this requirement, floor receptacle outlets satisfying this rule shall be located not more than ____ inches from the wall.
Raceways on exterior surfaces of buildings shall be: ____ and arranged to drain.
Raceways on exterior surfaces of buildings shall be: ____ and arranged to drain.
Which of the following are not standard size fuses of time inverse circuit breakers according to NEC?
Which of the following are not standard size fuses of time inverse circuit breakers according to NEC?
Which rooms listed below in a dwelling unit must always have a wall-mounted control device controlling a lighting outlet?
Which rooms listed below in a dwelling unit must always have a wall-mounted control device controlling a lighting outlet?
There shall be a minimum of one ____ ampere branch circuit for the outlet(s) in a dwelling unit.
There shall be a minimum of one ____ ampere branch circuit for the outlet(s) in a dwelling unit.
The maximum general-purpose branch circuit rating of a flat conductor cable is ____ amperes.
The maximum general-purpose branch circuit rating of a flat conductor cable is ____ amperes.
A storable swimming pool is capable of holding water to a maximum depth of ____ inches.
A storable swimming pool is capable of holding water to a maximum depth of ____ inches.
What is the meaning of approved?
What is the meaning of approved?
As defined in Article 100, a dwelling unit has the following feature(s):
As defined in Article 100, a dwelling unit has the following feature(s):
The prefix kilo- means ____.
The prefix kilo- means ____.
The prefix milli- means ____.
The prefix milli- means ____.
The NEC gives measurements in which system of units first?
The NEC gives measurements in which system of units first?
NRTL ____ electrical products to provide a basis for approval by inspectors in the field.
NRTL ____ electrical products to provide a basis for approval by inspectors in the field.
An electrician must not stand higher than the ____ rung from the top for extension ladders.
An electrician must not stand higher than the ____ rung from the top for extension ladders.
The NEC is a minimum ____ standard.
The NEC is a minimum ____ standard.
The open circuit voltage between the two terminals of a single-pole switch on a lighting circuit when the switch is in the off position?
The open circuit voltage between the two terminals of a single-pole switch on a lighting circuit when the switch is in the off position?
Listing or labeling of electrical equipment is done by a:
Listing or labeling of electrical equipment is done by a:
LOTO is required by ____.
LOTO is required by ____.
Published by the National Fire Protection Association (NFPA) ____ is the standard for electrical safety in the workplace.
Published by the National Fire Protection Association (NFPA) ____ is the standard for electrical safety in the workplace.
A receptacle outlet is ____.
A receptacle outlet is ____.
Where noncombustible surface material is used on walls or ceilings, outlet boxes must be mounted so that they will be set back not more than ____ from the face of the surface material.
Where noncombustible surface material is used on walls or ceilings, outlet boxes must be mounted so that they will be set back not more than ____ from the face of the surface material.
Certain kinds of boxes may be grouped together or ____.
Certain kinds of boxes may be grouped together or ____.
A ____ is an outlet intended for the direct connection of a lamp holder.
A ____ is an outlet intended for the direct connection of a lamp holder.
Article ____ contains much detail about outlet boxes, device (switch) boxes, pull boxes, junction boxes, and conduit bodies.
Article ____ contains much detail about outlet boxes, device (switch) boxes, pull boxes, junction boxes, and conduit bodies.
The plans show curved lines running between switches and various outlets. What do these lines indicate?
The plans show curved lines running between switches and various outlets. What do these lines indicate?
You can increase the total volume of a box by adding a mud ring that is ____.
You can increase the total volume of a box by adding a mud ring that is ____.
What is the cubic volume in inches for a 14 AWG conductor?
What is the cubic volume in inches for a 14 AWG conductor?
The purpose of electrical symbols on plans is ____.
The purpose of electrical symbols on plans is ____.
Direct current is described as ____.
Direct current is described as ____.
Current flows in only one direction is called unidirectional. It is also referred to as ____ current.
Current flows in only one direction is called unidirectional. It is also referred to as ____ current.
The effects of static electricity (electric charges) were noticed by the Greeks about ____ years ago.
The effects of static electricity (electric charges) were noticed by the Greeks about ____ years ago.
Objects charged with the same type of charge will push each other away. This is referred to as ____.
Objects charged with the same type of charge will push each other away. This is referred to as ____.
Objects charged with different types of charges will be drawn towards each other. This is referred to as ____.
Objects charged with different types of charges will be drawn towards each other. This is referred to as ____.
An element cannot be chemically subdivided into other elements. The smallest part of an element is ___.
An element cannot be chemically subdivided into other elements. The smallest part of an element is ___.
The part of an atom that has a positive charge is the ___.
The part of an atom that has a positive charge is the ___.
The nucleus of an atom contains ___.
The nucleus of an atom contains ___.
The atomic number of an element is the number of ___ in the nucleus.
The atomic number of an element is the number of ___ in the nucleus.
The law of charges states that like charges ____ and opposite charges ___.
The law of charges states that like charges ____ and opposite charges ___.
The valence shell of an atom is the ____ shell.
The valence shell of an atom is the ____ shell.
Valence electrons are contained in the ____ shell.
Valence electrons are contained in the ____ shell.
A conductor is normally made of atoms with ____ electrons in the valence shell.
A conductor is normally made of atoms with ____ electrons in the valence shell.
Electricity is the flow of ___.
Electricity is the flow of ___.
The most common method of producing electricity is through the use of ___.
The most common method of producing electricity is through the use of ___.
What is the term for an amount of charge equal to $6.25 imes 10^{18}$ electrons?
What is the term for an amount of charge equal to $6.25 imes 10^{18}$ electrons?
The force of electrostatic attraction or repulsion is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them. This is ____ law.
The force of electrostatic attraction or repulsion is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them. This is ____ law.
A flow of one coulomb per second passed a point on a circuit describes ___.
A flow of one coulomb per second passed a point on a circuit describes ___.
The speed of travel of electricity in a conductor is ____ the speed of light.
The speed of travel of electricity in a conductor is ____ the speed of light.
In order to have a flow, a circuit must be ___.
In order to have a flow, a circuit must be ___.
If a circuit is open, current ____ flow.
If a circuit is open, current ____ flow.
In a circuit, when the two conductors leading from the power source touch metal-to-metal, this is called a ____ circuit.
In a circuit, when the two conductors leading from the power source touch metal-to-metal, this is called a ____ circuit.
The neutral conductor is also referred to as the ____ conductor.
The neutral conductor is also referred to as the ____ conductor.
The unit of electromotive force is the ____.
The unit of electromotive force is the ____.
The unit of electrical 'pressure' that causes current to flow is called a ___.
The unit of electrical 'pressure' that causes current to flow is called a ___.
The unit of resistance is the ____.
The unit of resistance is the ____.
Opposition to current flow is called ___.
Opposition to current flow is called ___.
An opposition to current flow that occurs in alternating current circuits is called ___.
An opposition to current flow that occurs in alternating current circuits is called ___.
The unit of electrical power is the ____.
The unit of electrical power is the ____.
An electrical device is listed as 3000 watts. Approximately how much horsepower is this?
An electrical device is listed as 3000 watts. Approximately how much horsepower is this?
The statement 'current is directly proportional to voltage and inversely proportional to resistance' is known as _____ law.
The statement 'current is directly proportional to voltage and inversely proportional to resistance' is known as _____ law.
An electrical circuit has a voltage of 50V and a resistance of 5 ohms. What is the value of the current?
An electrical circuit has a voltage of 50V and a resistance of 5 ohms. What is the value of the current?
An electric motor is running on 120V. The current is measured to be 2A. How many ohms of resistance is the motor?
An electric motor is running on 120V. The current is measured to be 2A. How many ohms of resistance is the motor?
An electric circuit has a resistance of 20 ohms. The current is measured to be 6A. How many volts are applied to the circuit?
An electric circuit has a resistance of 20 ohms. The current is measured to be 6A. How many volts are applied to the circuit?
A toaster is listed as 1560W. When it is plugged into a 120V circuit and starts to make toast, how many amperes will it draw?
A toaster is listed as 1560W. When it is plugged into a 120V circuit and starts to make toast, how many amperes will it draw?
A static electric charge is an electric charge which ___ moving.
A static electric charge is an electric charge which ___ moving.
Electric charges that are not moving are called ___ charges.
Electric charges that are not moving are called ___ charges.
Electrostatic charges occur on ___.
Electrostatic charges occur on ___.
Bringing a charged test object near a ball of a charged electroscope causes the leaves to move closer together. This indicates that the test object charge is the ____ polarity as the electroscope charge.
Bringing a charged test object near a ball of a charged electroscope causes the leaves to move closer together. This indicates that the test object charge is the ____ polarity as the electroscope charge.
Protecting objects from lightning strikes can be done by connecting a conductor from the earth to a piece of metal usually mounted on the roof of a building. The piece of metal is called a lightning _____.
Protecting objects from lightning strikes can be done by connecting a conductor from the earth to a piece of metal usually mounted on the roof of a building. The piece of metal is called a lightning _____.
If you walk across a carpet, touch a doorknob and get a shock, the shock was the result of a ___ static charge.
If you walk across a carpet, touch a doorknob and get a shock, the shock was the result of a ___ static charge.
Lodestone is a name for a naturally occurring magnetic material that is also called _____.
Lodestone is a name for a naturally occurring magnetic material that is also called _____.
A(n) ___ magnet is a magnet that retains its magnetism without any applied power.
A(n) ___ magnet is a magnet that retains its magnetism without any applied power.
Permanent magnets retain their magnetism ____.
Permanent magnets retain their magnetism ____.
The three substances that form natural magnets are ___.
The three substances that form natural magnets are ___.
Magnetic lines of force are called ____.
Magnetic lines of force are called ____.
A basic law of magnetism states that like poles ____ and opposite poles ____.
A basic law of magnetism states that like poles ____ and opposite poles ____.
A magnet that produces a magnetic field as the result of current flow in a conductor is called a(n) _____ magnet.
A magnet that produces a magnetic field as the result of current flow in a conductor is called a(n) _____ magnet.
The strength of an electromagnet is primarily proportional to its _____.
The strength of an electromagnet is primarily proportional to its _____.
The measure of a material's willingness to be magnetized is called ____.
The measure of a material's willingness to be magnetized is called ____.
In a circuit that has very little resistance, almost any applied voltage will result in huge amounts of current. This is called _____ circuit.
In a circuit that has very little resistance, almost any applied voltage will result in huge amounts of current. This is called _____ circuit.
When two or more resistors are connected in a series across a voltage supply, each of the resistors will have a voltage across it. The resistor network is known as a ____.
When two or more resistors are connected in a series across a voltage supply, each of the resistors will have a voltage across it. The resistor network is known as a ____.
Resistors which have only one ohmic value are called _____ resistors.
Resistors which have only one ohmic value are called _____ resistors.
When resistors are manufactured, the processes are not perfectly exact. Each resistor may be slightly different from the next one. The plus and minus limits of a resistor's marked value is called ____.
When resistors are manufactured, the processes are not perfectly exact. Each resistor may be slightly different from the next one. The plus and minus limits of a resistor's marked value is called ____.
A resistor which is made by applying a film of carbon to a ceramic rod is the ___ resistor.
A resistor which is made by applying a film of carbon to a ceramic rod is the ___ resistor.
Study Notes
Electrical Safety and Current
- The foremost rule of electrical safety is to always think before acting.
- When possible, use only one hand to avoid a current passing through the heart, which can be lethal.
- Electric currents in the range of 100 to 200 milliamperes are generally fatal.
- Heart fibrillation occurs when the heart starts quivering, which can be reset by a defibrillator delivering a current of 200 mA.
Regulatory Standards
- The US Secretary of Labor enforces OSHA (Occupational Safety and Health Administration) regulations.
- OSHA's mission is to promote safe and healthful workplaces.
- An MSDS (Material Safety Data Sheet) is essential for documenting safety information about materials used in the workplace.
Equipment Lockout and Ground Faults
- A padlock used for equipment lockout should be held by the person working on it.
- A ground fault represents an unintended path for electrical current to the ground.
- Ground-fault detectors typically open a circuit at approximately 5 milliamperes, providing additional safety.
Fire Classes and Electrical Codes
- Four classes of fires:
- Class A: Wood and paper
- Class B: Flammable liquids like grease and gas
- Class C: Electrical fires
- Class D: Fires involving burning metals
- Grounding is covered in NEC (National Electrical Code) section 250.
Electrical Components and Measurements
- Accessible outlets must allow operation, renewal, and inspection without obstruction.
- Bonding jumpers ensure reliable electrical conductivity between connected metal components.
- Askarel is a term for a group of nonflammable synthetic chlorinated hydrocarbons used for electrical insulation.
Circuit and Voltage Regulations
- Receptacle outlets need to be located no further than 6 feet from any point along the wall, with floor receptacles within 18 inches of the wall.
- Electrical raceways outside buildings must be listed or approved for use in wet locations.
Common Knowledge in Electrical Measurements
- Standard time-inverse circuit breakers according to NEC do not include 55 amp fuses.
- Every habitable room in a dwelling requires a wall-mounted control device for lighting.
- A minimum of one 20-amp branch circuit is required for outlets in a dwelling unit.
Basic Electrical Concepts and Units
- The prefix kilo- signifies one thousand, while milli- indicates one thousandth.
- The NEC primarily presents measurements in the SI metric system.
- An NRTL (Nationally Recognized Testing Laboratory) lists electrical products for inspector approval.
Current, Voltage, Impedance, and Resistance
- The electrical pressure causing current to flow is measured in volts, and the unit of resistance is ohms.
- Ohm's law states that current (I) is directly proportional to voltage (V) and inversely proportional to resistance (R).
- Static electricity occurs on insulators and is characterized by charges that do not move.
Magnetism and Conductivity
- Permanent magnets retain magnetism without external power, whereas electromagnets require current flow to generate a magnetic field.
- The three elements commonly forming natural magnets are iron, nickel, and cobalt.
- The strength of an electromagnet depends on ampere turns, highlighting the importance of current in magnetism.
Resistors and Circuit Behavior
- Resistors can be fixed in value, and variations in their manufacturing are noted as tolerance.
- In series circuits, resistors form a voltage divider, distributing voltage across each resistor based on their resistive values.
General Knowledge for Electrical Work
- Avoid standing on the top four rungs of an extension ladder while working.
- Static charges can create nuisance shocks, such as touching a doorknob after walking on carpet.
- Understanding the properties of substances and their charges is crucial for electrical safety and effective circuit design.
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Description
This quiz covers essential concepts in electrical safety and its related risks. It includes crucial facts such as the important safety rules, the danger of current passing through the heart, and the effects of electrical shocks. Perfect for anyone studying or working in the electrical field.
