PRELIM Flashcards
1
Q
Presence and flow of electric charge
A
Electricity
2
Q
Electricity can be ________ or _________
A
Static or current
3
Q
It is a stationary electric charge
A
Static
4
Q
How does static electricity happen?
A
when there is an unbalanced charges
5
Q
What is an unbalanced charge?
A
Losing or gaining electron
6
Q
It is typically produced by friction, which causes sparks or crackling or the attraction of dust or hair
A
Static Electricity
7
Q
Flow of charge particle
A
Current Electricity
8
Q
In current electricity , what is moving?
A
Electrons
9
Q
Mass of charges proton
A
1.672 X 10 ^ -27
10
Q
Mass of charge electron
A
9.107 x 10 ^ -31
11
Q
Center of atom
A
Nucleus
12
Q
Where the protons and neutron located
A
Nucleus
13
Q
Revolve around the orbits of valence shells around the nucleus
A
Electrons
14
Q
It is an electrical property of the atomic particles of which matter consist, measured in coulombs (C).
A
Charge
15
Q
How many electrons per 1 charge
A
1 C of charge = 6.25 x 1018 electrons
16
Q
How to know if a body has charge ?
A
if it has either an excess or
deficit of electrons from its normal values.
17
Q
3 major classes of electrical material
A
Conductor, semi-conductor, insulator
18
Q
Material that has free electrons. Their electrons flow easily between atoms
A
Conductor
19
Q
How many valence electron in outer orbit
A
1 - 3
20
Q
have free electrons, but not as
many as conductors.
These materials have low
conductivities.
A
Semi - conductor
21
Q
How many valence for semi-conductor ?
A
4
22
Q
Object that does not
allow charge to flow.
Have very few free
electrons.
A
Insulator
23
Q
5-8 valence electrons in
outer orbit
A
Insulators
24
Q
Examples of insulators
A
Glass, mica, quartz
25
Examples of semi conductors
Germanium and silicon
26
Examples of conductors
Silver, copper, aluminum, Gold
27
a closed loop made of conductors and other electrical
| elements through which electric current can flow
Electric circuit
28
Parts of electric circuit
Control, power source, conductors
29
Types of circuit
Short, Open and closed
30
Circuit that allows the
| current follows the unintended path
Short circuit
31
Two circuit component
Active and Passive
32
Can generate power into a circuit and
are capable of electrically controlling and amplifying the flow of electrical current, whereas passive components cannot.
Active component
33
Component of a circuit that can either store or consume power but not electricity
Passive component
34
Example of Active Component
```
Batteries
Power supply
Power transformers
Dynamos
Amplifiers
```
35
Example of Passive Component
Capacitors
Resistance
Transducer,
Inductor
36
is the
movement of electrons through a
conductive material.
Electricity
37
It refers to the number of
charges that move around a
circuit per second
Current
38
Ampere is named after
Andres M. Ampere
39
Formula of Ampere
I = Charge / time (C/s)
40
assumes that current flows out of
the positive side of the battery,
through the circuit, and back to the
negative side of the battery.
Conventional Current Flow
41
It flows out of the negative side of
the battery, through the circuit,
and back to the positive side of
the battery.
Electron Flow
42
It is a current that remains
| constant with time.
Direct Current
43
Direct current flows only to ________
One direction
44
The normal
source of a DC electricity is
____________-
the dry cell or storage battery
45
it is the current that constantly reverses its direction of
flow.
Alternating Current
46
What generates the Alternating Current?
Generator
47
is the energy
required to move a unit
charge through an element
from one point to the other
Volts
48
Formula of volts
J/C
49
Volts is named after
Alessandro C. Volta
50
Who invented the first Batteryy?
Alessandro C. Volta
51
How many columbs in an electron or proton?
1.602 x 10 -19 coulombs
52
is the opposition to the
current flow and at the same time
causing electrical energy to be
converted to heat energy
Resistance
53
Ohms Law states that
It states that the current in a resistive circuit is directly proportional to
its applied voltage (I ∝ V) and inversely proportional to its resistance (I 1Τ∝ R)
54
Unit of Power
Joules/sec
55
Power is named after
James Watt
56
Four (4) factors that affect the resistance of a
| conductors
Length
temperature
Cross sectional Area
Resistivity (based on material)
57
thinner the wire, greater the
thinner the wire, greater the resistance
58
Formula of resistivity
pL/A
ohm cm (cm)
------------------
cm
59
area of a circle having a diameter (d) of one
| mil.
CIRCULAR MIL (CM)
60
How many mils in 1 inch
1000
61
Formula of circular mils
diameter ^2
62
a measure of the material’s ability to conduct electric
| current.
Conductance
63
What is the reciprocal of conductance
Resistance
64
is a unit of conductance
Siemens
65
Siemens was named after _________
Ernst Werner von Siemens
66
Formula for siemens
Ampere / Volt
| 1/R
67
How to calculate total resistance of series
R1 + R2 + R3 + R4
68
How to calculate voltage of series
Vr1 + Vr2 + Vr3 = Vt
69
How to calculate total resistance of Parallel
1/ (1/R1) + (1/R2) ...
70
```
ON-ON switch
This switch can be ON in both
positions, switching on a separate
device in each case. It is often called
a changeover switch.
```
SPDT Switch
71
This type of switches is used for
controlling two different circuits at a
time.
Dpst switch
72
Momentary switch - normally open.
This switch is in ON state when the
button is pressed otherwise it is in
OFF state.
Pushbutton switch
73
Generates constant voltage.
DC Voltage
74
Generates sinusoidal voltage.
AC Voltage
75
Generates constant current
DC Current
76
Generates sinusoidal current
AC Current
77
Generates voltage that can vary the
| magnitude.
Variable DC Current
78
Measures voltage. Has very high
| resistance. Connected in parallel
Voltmeter
79
Measures electric current. Has near
| zero resistance. Connected serially
Ammeter
80
Measures electric power.
Wattmeter
81
A device that measures the amount
of electric energy consumed by
a residence, a business, or an
electrically powered device
AC Watt-hour meter
82
a device that can
| transform electric energy into mechanical energy
Electric motor
83
Generates light when current flows through.
Lamp/bulb
84
Used for zero potential reference and electrical
| shock protection.
Earth Ground
85
device used on electrical
power systems and telecommunications systems
to protect the insulation and conductors of the
system from the damaging effects of lightning.
Lightning Arrester
86
is where the wires connected to the load side of the
| meter enter the house or building.
Service entrance
87
is a component of an
electricity supply system that divides an
electrical power feed into subsidiary circuits,
Main distribution panel board
88
Subscript letters indicate special variations
Special Purpose Outlet
89
. Used to power
most of the electrical equipment you use in
your home on a daily basis, such as TVs,
fans, countertop kitchen appliances, and so
Duplex Convenience
90
used in building construction
and consists of a square box or housing that
provides protection and a safety barrier for
electrical connections.
Junction Box
91
it s the electrical cable that
carries power from the main circuit breaker panel
to the first electrical box, plug, or switch in
the circuit.
Circuit Homerun
92
Three single pole switches on one switch plate
| controlling one circuit of light per switch.
Triplex
93
Two single pole switches on one switch plate
| controlling one circuit of light per switch.
Duplex
94
An electrical switch having two blades with their
contacts for simultaneous opening or closing
both sides of a circuit
Double Pole Switch
95
An electric switch used in house wiring so that a
light may be turned on or off at three or more
places
4 way switch
96
Change AC voltage from high to low or low to
| high.
Transformer
97
Coil / solenoid that generates magnetic field
Inductor
98
Allows current flow in one direction only -
| left (anode) to right (cathode).
Diode
99
Allows current flow in one direction, but also
can flow in the reverse direction when above
breakdown voltage.
Zener diode
100
a diode with low forward
| voltage drop and it can switch rapidly.
Schottky Diode
101
The capacitance
of this diode varies according to the applied
input voltage
Varactor / Varicap Diode
102
Diode that can
switch very fast and can perform well in
microwave frequency range
Tunnel Diode
103
a standard diode symbol with
two small arrows showing the emission of
light.
LED
104
detects the light
| energy and converts it into current or voltage
Photodiode
105
Outputs 1 when input is 0
Not Gate
106
Outputs 1 when both inputs are 1.
And Gate
107
Outputs 0 when both inputs are 1.
NAND gate
108
Outputs 1 when any input is 1.
Or Gate
109
Outputs 1 when any input is 1.
Nor Gate
110
Allows current flow when high potential at
| base
NPN Bipolar Transistor
111
Allows current flow when low potential at
| base
PNP Bipolar
| Transistor
