[Electrical Fundamentals] Flashcards
What is the opposition of current flow?
Resistance (R) Ohm
What are elements that transfer electrons very readily?
Conductors
What are formed when several cells are connected together to increase electrical output?
Batteries
What should be affixed to an affected circuit breaker or power source before starting any electrical work?
Red DANGER tag
What is voltage produced by pressure?
Piezoelectricity
What are needed to complete a circuit?
- Power source
- Load
- Conductor
What is a reasonable precaution to take when making contact with energized electrical equipment?
Work with one hand if possible
What are the forces causing magnetization represented by?
Magnetic lines of force
What is produced when two dissimilar substances are immersed in a solution that produces a greater action on one substance than on the other?
Voltage by chemical action
When working on energized circuits, what should be tagged out at the nearest source of electricity for the component being serviced?
Power source
What is energy contained in an object because of its position?
Potential energy
Rules for parallel circuits
- More than one path
- Voltage - CONSTANT
- Current - ADD
- Resistance - LESS THAN LEAST
- Power - SUM
How many valence electrons for conductors, semi-conductors, and insulators?
- Conductors - Less than 3
- Semi-conductors - 4
- Insulators - 5-8
What is electricity at rest?
Electrostatics
What are two or more elements that are chemically combined that can be separated by chemical means, but not by physical means?
Compound
What should be done before working on de-energized equipment?
Discharge capacitors
What is the difference in potential between two bodies?
Electromotive force (EMF) or voltage
What are used to measure temperature and are used in heat-sensing devices in automatic temperature control equipment?
Thermocouples
What is a substance that cannot be reduced to a simpler substance by chemical means?
Element
What is the force that allows an electron to be available to be attracted to a positive ion?
Voltage (Volts - V)
What use magnets to convert mechanical motion into electrical energy?
Generators
What is the total number of magnetic lines of force leaving or entering the pole of a magnet?
Magnetic flux
Number of flux lines per unit area is called flux density
What is the smallest particle of an element that retains the characteristics of that element?
Atom
What is the property of material that enables it to attract to pieces of iron?
Magnetism
What is the opposition to magnetic lines of force?
Reluctance
Rules for series circuits
- One path
- Voltage - ADD
- Current - CONSTANT
- Resistance - ADD
- Power - SUM
What is anything that prevents or resists the maximum flow of electrons?
Resistance (Ohms)
What is adding impurities to a semi-conductor?
Doping
What use magnets to convert electrical energy into mechanical energy?
Electrical motors
What flows when one coulomb of charge passes a point in one second?
Current of ampere
What are the six ways to produce an EMF?
- Friction
- Pressure
- Light
- Heat
- Chemical reaction
- Magnetic induction (magnetism)
What have an extremely high resistance to the flow of electrons?
Insulators
What is a device that measures current?
Ammeter
What is voltage produced by heating the joint where two unlike metals are joined?
Thermoelectricity
What is the process by which an atom loses or gains electrons?
Ionization
What is the quantity of electrons passing a specific point in a circuit in a given time period?
Current (Amperes - A)
What are the lines that represent the field about a charged body?
Electrostatic lines of force
What are the three methods for calculating resistance in a parallel circuit?
- Like method
- Product over sum
- Inverse reciprocal method
What is the ease with which magnetic lines of force distribute themselves throughout the material?
Permeability
What is the directed flow of electrons?
Electric current
What is the space surrounding a magnet where magnetic forces act?
Magnetic field
What law states: “Charged bodies attract or repel each other with a force that is directly proportional to the product of their individual charges and is inversely proportional to the square of the distance between them.”
Coulomb’s Law
What is the product of force and displacement?
Work
Who are tags signed by?
Chief engineer
What are the three general classifications of magnets?
- Bar
- Ring
- Horseshoe (most frequently used)
What are the three things needed for magnetic induction?
- Conductor
- Magnetic field
- Relative motion
What is anything that occupies space?
Matter
What is a combination of two or more elements, one of which must be metal?
Alloy
What is the best conductor?
Silver
What is energy contained in an object due to its motion?
Kinetic energy
What is the ability to do work?
Energy
What is the amount of magnetism that remains in a temporary magnet?
Residual magnetism
Quay are the two classifications if artificial magnets?
- Temporary
* Permanent
What is the space between and around charged bodies?
Electric field of force
What is the choice for fighting electrical fires?
CO2
What is a combination of elements and/or compounds that are not chemically combined and that can be separated by physical means?
Mixture
What is any particle that is a chemical combination of two or more atoms?
Molecule
What is anything between a conductor or insulator?
Semiconductor
