Part of the nucleus of an atom is made up of protons. Each
proton has a positive electrical charge and attracts electrons;
neutrons form the remainder of the nucleus. Neutrons are
electrically neutral. They can neither attract nor repel other
electrical charges
Name
Charge
Mass (kg)
Proton
Positive Charge
1.672 𝑥 10−27
Electron
Negative Charge
9.107 𝑥 10−31
Neutron
No charge
1.672 𝑥 10−27
One or more electrons revolve continuously around the
nucleus of an atom (just as the planets revolve about the sun).
Electrons possess a negative electrical charge and are very
much lighter in weight than protons. All electrons are alike
regardless of the atoms of which they are a part. An atom
contains the same number of electrons as protons. For
example, the aluminum atom has thirteen electrons and
thirteen protons.
Element
No. of electrons
No. of Protons
Number of Neutrons
Valence Electrons
Copper
29
29
34
1
Aluminum
13
13
14
3
Germanium
32
32
41
4
𝑸
𝑰=
𝒕
•
𝐼 = 𝑐𝑢𝑟𝑟𝑒𝑛𝑡 𝑓𝑙𝑜𝑤, 𝑖𝑛 𝑎𝑚𝑝𝑒𝑟𝑒𝑠 (𝐴)
𝑄 = 𝑡𝑜𝑡𝑎𝑙 𝑐ℎ𝑎𝑟𝑔𝑒 𝑚𝑜𝑣𝑖𝑛𝑔, 𝑖𝑛 𝑐𝑜𝑢𝑙𝑜𝑚𝑏𝑠 𝐶
𝑡 = 𝑡𝑖𝑚𝑒 𝑜𝑓 𝑜𝑐𝑐𝑢𝑟𝑒𝑛𝑐𝑒, 𝑖𝑛 𝑠𝑒𝑐𝑜𝑛𝑑𝑠 (𝑠)
•
𝟔. 𝟐𝟓 𝒙 𝟏𝟎𝟏𝟖 𝒆𝒍𝒆𝒄𝒕𝒓𝒐𝒏𝒔 𝒐𝒓 𝒑𝒓𝒐𝒕𝒐𝒏𝒔
𝑾
𝑬=
𝑸
𝐸 = 𝐸𝑀𝐹 𝑜𝑟 𝑣𝑜𝑙𝑡𝑎𝑔𝑒 𝑜𝑟 𝑝𝑜𝑡𝑒𝑛𝑡𝑖𝑎𝑙 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒, 𝑖𝑛 𝑣𝑜𝑙𝑡𝑠 (𝑉)
𝑊 = 𝑒𝑛𝑒𝑟𝑔𝑦 , 𝑖𝑛 𝐽𝑜𝑢𝑙𝑒𝑠 (𝐽)
Q = 𝑐ℎ𝑎𝑟𝑔𝑒, 𝑖𝑛 𝑐𝑜𝑢𝑙𝑜𝑚𝑏𝑠 (𝐶)
•
•
Current Types
• Direct current (DC) is the movement of electrons in one
direction in a conductor.
• Pulsating direct current is a current in one direction that
varies in intensity at a regular interval of time.
• Alternating current (AC) is a current that changes in
direction and intensity at a regular interval of time.
•
Ω
𝑷 = 𝑬𝑰
𝑾 = 𝑷𝒕
𝑊 = 𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐 𝑒𝑛𝑒𝑟𝑔𝑦, 𝑖𝑛 𝑗𝑜𝑢𝑙𝑒𝑠 𝐽
𝑃 = 𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐 𝑝𝑜𝑤𝑒𝑟, 𝑖𝑛 𝑤𝑎𝑡𝑡𝑠 𝑊
𝐼 = 𝑐𝑢𝑟𝑟𝑒𝑛𝑡, 𝑖𝑛 𝑎𝑚𝑝𝑒𝑟𝑒𝑠 𝐴 ,
𝐸 = 𝑒𝑚𝑓 𝑜𝑟 𝑣𝑜𝑙𝑡𝑎𝑔𝑒, 𝑖𝑛 𝑉
𝑡 = 𝑡𝑖𝑚𝑒, 𝑖𝑛 𝑠𝑒𝑐𝑜𝑛𝑑𝑠 (𝑠)
•
•
•
•
•
•
An electric circuit contains a closed path for
providing a flow of electrons from a voltage
source or current source. The elements
present in an electric circuit will be in series
connection, parallel connection, or in any
combination of series and parallel
connections.
BASIC PARTS OF A CIRCUIT:
1.SOURCE
An electric circuit contains a closed path for
2.WIRES/CONDUCTORS
providing a flow of electrons from a voltage
3.LOAD
source or current source. The elements
present in an electric circuit will be in series
4.SWITCH
connection, parallel connection, or in any
combination of series and parallel
connections.
All DC sources of electrical pressure
have two terminals to which electrical
devices
are connected. These terminals have
electrical polarity. One terminal is the
positive terminal,
whereas the other is the negative
terminal.
Active Elements deliver power to other elements,
which are present in an electric circuit. Sometimes,
they may absorb the power like passive elements.
That means active elements have the capability of
both delivering and absorbing power.
Passive Elements can’t deliver power (energy) to other
elements, however they can absorb power. That
means these elements either dissipate power in the
form of heat or store energy in the form of either
magnetic field or electric field.
Examples: Voltage sources and current sources.
Examples: Resistors, Inductors, and capacitors
If a current of 2A flows through a point
in a wire for 30 seconds, how many
coulombs pass through the point in the
wire?
What quantity of charge must be
delivered by a battery with a potential
difference of 100 V to do 500 J of work?
A radio receiver draws 0.9 A at 110 V. If
the set is used 3 hours per day, how
much energy does it consume in 10
days?