D1 Flashcards
Anything that occupies space or has mass is referred to as
Matter
A substance that is made up of more than one type is a
Compound
The atomic number of an element refers to the number of _____ in the ____ of an atom
Protons, nucleus
The maximum number of electrons allowed in Valence orbit.
8
In orbits farther from the nucleus, the energy possessed by electrons
Increases
An electron that has broken loose from its atom is a
Free electron
Semiconductors contain ____ valence electrons.
Four
Most metals are good
Conductors
The smallest independent portion that a substance can be broken down to is a
Molecule
The smallest portion an element can be broken into
Atom
Negative charge is called
Anion
Positive charge is called
Cation
The first Law
Like charges repel an unlike charges attract
The force between two charges at rest is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them.
Coulomb’s Law
Each atom shares its valence electrons with others around it
Is a Metallic Bond
An atom that has a positive charge possess _____ electrons then protons
Fewer
Like charges ____ and unlike charges _____
Repel and attract
Electrostatic charge becomes a hazard
Lightening and fuel handling
The body can receive an electrostatic charge by
Friction (contact)
Conduction
Induction
Electrons flow ____ to ____
(-) to (+)
Negative to positive
A force that acts at a distance with no contact
A Field force
____ refers to the charge at one point with respect to another
Polarity
Two dissimilar materials rubbed together is the _____ effect
Triboelectric effect
The work per unit charge done by a source of energy on electric charges, to move them against an electric field.
Electromotive Force (emf)
Piezoelectric effect aka
Pressure
Electrochemical effect aka
Chemical —> battery
Thermoelectric effect aka
Heat
Thermocouples used in series is called?
Thermopile
Light
Extra energy causes the electrons to leave their atoms, and current to flow.
Photovoltaic effect
Name of the device which uses the photovoltaic effect
Photovoltaic cell
Magnetoelectric effect aka
Magnetism
The law of the conservation of energy is
Energy may neither be created or destroyed
6.24 X 10^18 is referred to as a
Coulomb
The term used to represent opposition to current flow in a circuit
Resistance
Charge
Q
Coulomb
C
Power
P
Watt
W
Resistance
R
Ohm
Upside down horseshoe
Energy emf units
E
Volt
V
Current units
I
Ampere
A
Why diagram is easiest to understand for a person with little knowledge of electricity is a ____ diagram.
Pictorial
A schematic diagram that shows power source as two vertical lines on either side is a ____ diagram
Ladder
Difference between block diagram components and one-line diagram components.
Block diagram uses blocks.
One line diagram uses symbols.
Schematic diagrams do not show
The physical relationship.
But rather the electrical relationship.
Type of diagram where components are shown as they appear are _____ diagrams
Pictorial
The flow chart style is the ____ diagram.
Block.
Circuit map is a _____ type of diagram.
Wiring.
Diagram with a three-dimensional component view is a ____ diagram.
Pictorial
Does not show the individual conductors is a ____ diagram.
One-line or Block
A device that changes electrical energy into other forms of energy is
a Load
Define a short circuit
A parallel path of low resistance.
Two types of damage due to high current
Thermal and Mechanical
Current flows through a load from____ to ____
Negative to positive
-) to (+
A charge at one point with respect to another.
Polarity
How does a fuse or breaker protect from excessive current.
It creates an opening in the circuit
When a switch is open it is____
Off
Current flows through a power SOURCE from ____ to _____
Positive to negative
+) to (-
Source, load and conductors are
The three necessary components to a circuit.
To stop the load the switch must be____
Open
why are resistors used
Creating heat
Regulating voltage
Controlling Current
resistors are rated in
ohms and watts
three types of resistors
wire-wound
film resistor
carbon composition
Carbon composition has the ___watts rating
lowest
Adjustable resistors are normally ___type
wire-wound
More common name for an Edison fuse
plug fuse
What was the fault with edison fuses
they could be replaced with one of a higher amperage
A circuit breaker can operate on ___ or____
thermal or magnetic action
knife blade fuses are used when the Amperage is in excess of
60A
Trip- free means what?
that one can not hold the Breaker in the closed position once the circuit is tripped.
CEC classes low voltage as
31V - 750V
DRT cable is used for
ranges and dryers
bus bars determine the ___rating of distribution panels
Amperage
general service cables are common for
hard usage type for portable equipment
each circular mil is = to ___square mils
0.7854
Copper or aluminum which has the lower resistance
Copper
R of Alumium = R of copper
x 1.64
so 10 ohms of copper x1.64 = 16.4 ohms aluminum
5 factors that determine amps/ current flow in a conductor
type of conductor material size Insulation type Ambient temperature method of insulation.
Atoms become stable if they have 8 electrons in their valence orbit. This is called
A Stable Octet
Kirchhoff’s voltage law states that :
the sum of all voltages across resistors or loads is equal to the applied voltage
_________ cannot be recharged, while ___________ can be recharged.
Primary cells, secondary cells
Connecting cells in series (- to +) increases their ________, while connecting them in parallel (- to - and + to +) increases their
voltage rating, current rating
The basic meter movement used for many analog instruments is.
the moving-coil galvanometer, or the D’Arsonval movement
Voltage is measured in
Current is Measured in (devices)
Parallel
Series
