This document provides an overview of electrical wiring diagrams and the components of a simple circuit. It discusses direct current and alternating current, and defines the key components of a simple circuit including an AC/DC source, fuse, wires, switch, and load. The document then explains Ohm's Law, providing the mathematical relationship between voltage, current, and resistance, and examples for applying Ohm's Law to calculate unknown values in a circuit.

1. ELECTRICAL
WIRING
DIAGRAM
WEEK 7

2. Content Standard
The learners demonstrate an understanding
of concepts and underlying principles in
terminating and connecting electrical wiring
and electronics circuits.

3. Performance Standard
The learners demonstrate an understanding
of concepts and underlying principles in
terminating and connecting electrical wiring
and electronics circuits.

4. Session Objectives
After going through this lesson, you are
expected to:
1.Characterize types of wiring diagram.
2.Checked components of a circuit using the
Ohms Law.
3. Value the importance of the knowledge gained
in the lesson.

5. Magic Triangle

6. Electrical Wiring Diagram
Electrical Theory:
1. Direct Current and
2. Alternating Current

7. Electrical Wiring Diagram
Direct Current or DC is the first type of current because
it was easy to produce. This type of current always flows
in one direction. One of the disadvantages of using DC
is the excessive voltage drop and power loss in the
power lines in a long distance transmission. Batteries
are common sources of direct current.

8. Electrical Wiring Diagram

9. Components of a Simple Circuit
A Simple circuit contains the minimum
things needed to have a functioning electric
circuit. A simple circuit requires the
following:

10. Components of a Simple Circuit
AC/DC source
Equipment that will operate on either an AC or DC
power source.
Battery – A DC voltage source containing two or
more cells that convert chemical energy to electrical
energy.
Cell ‐ Single unit used to convert chemical energy
into a DC electrical voltage.

11. Components of a Simple Circuit
Fuse
Fuse is a safety device used to protect an electrical circuit from
the effect of excessive current.
A fuse is usually rated in Amperes, which represent the
maximum continuous current it could handle without blowing.
The most popular type of fuse in Electronics is 3AG type. This
code describes the case size and material where “G” indicates a
glass materials and “A” indicates that intended for automotive
application. A 3AG fuse measures approximately 32mm x 6mm.

12. Components of a Simple Circuit
Wires and Cable
A stranded conductor is a conductor composed of a group
of wire or any combination of group of wires. The wires in a
stranded conductor are usually twisted together and not
insulated from each other.
A cable is either a stranded conductor (single‐conductor
cable) or a combination of conductors insulated from one
another (multiple‐conductor cable).

13. Components of a Simple Circuit
Wires and Cable
A wire is a single slender rod or filament
of drawn metal.
A conductor is a wire suitable for
carrying an electric current.

14. Components of a Simple Circuit
Switch and its function
Switch is a device used to break an
electric current or transfer it to another
conductor.
A switch is a mechanical device used to
connect and disconnect a circuit at will.

15. Components of a Simple Circuit
Switch function
 When the switch is closed, the electron finds an
interrupted path in the circuit.
 Open is the OFF position of the switch, while closed is
the ON position.
 When the switch is opened, the current delivered by the
power supply is normally insufficient to jump the switch
gap in the form of an arc and the electron flow in the
circuit is blocked.

16. Components of a Simple Circuit
Load – a source drives a load. Whatever
component or piece of equipment is connected
to a source and draws current from a source is a
load on that source.
Bulb
Appliances

17. Ohm’s Law
Ohm’s law states that, for a constant current,
the current in a circuit is directly proportional to
the total voltage acting in the circuit and
inversely proportional to the total resistance of
the circuit. The law may be expressed by the
following equation if the:

18. Ohm’s Law
Current (I) is in amperes,
Electromotive force - EMF (E)is in volts,
and the
Resistance (R) is in ohms.

19. Ohm’s Law
The relationship of the foregoing three
variables was discovered by Georg Simon
Ohm, who theorized that current is in direct
proportion to resistance. The relationship is
explained algebraically, using this formula:

20. Ohm’s Law
Resistance (R) = E/I
Voltage (E) = I x R
Current (I) = E/R
where:
E – EMF in Volts
R – Resistance
I – Current in Amperes

21. Magic Triangle

22. Ohm’s Law
https://www.electronics-tutorials.ws/dccircuits/dcp_2.html

23. Ohm’s Law
Example (1):
An electronic device has a resistance of 20 ohms
and a current of 15 A. What is the voltage across
the device?
Solution: V = I x R
V = 15A x 20Ω
V = 300

24. Ohm’s Law
Example (2):
A 3V potential difference is applied across a 6Ω
resistor. What is the current that flows into the
resistor?
Solution: I = V ÷ R
I = 3V ÷ 6Ω
I = 0.5A

25. Ohm’s Law
Example (3):
An alarm clock draws 0.5 A current when
connected to a 120 V circuit. Find its resistance.
Solution: R = V ÷ I
R = 120V ÷ 0.5A
R = 240 Ω

26. Practice Exercise
Find the unknown value using Ohm’s Law
1. An electronic device has a resistance of 20 ohms and
a current of 15 A. What is the voltage across the device?
2. A 3V potential difference is applied across a 6 Ω
resistor. What is the current that flows into the resistor?

27. Practice Exercise
3. A current of 0.2 A passes through a 1.4 Ω resistor.
What is the voltage across it?
4. In a circuit, the potential drop across the 10 Ω -
resistor is 100 V. What is the current through the
resistor?
5. An alarm clock draws 0.5 A current when connected
to a 120 V circuit. Find its resistance.

28. Valuing
As a student, how will you apply the
knowledge and skills in Ohm’s Law in your
daily life?

29. Application
Find the unknown value using Ohm’s Law
1. What size resistor would produce a 3 Amp
current flow with a 12 Volt battery?
2. What is the Voltage of a circuit that has a
resistance of 5 Ω and a current of 2 A?

30. Application
3. If the battery produced 12.6 Volts what would be the
current flow for a 6 Ohm resistor? 4. How many Volts
would we need to produce a current flow of 8 Amps
through a 6 Ohm resistor?
5. The circuit has a 24-volt battery, and the resistor is 8
ohms. How many amps are running through the
circuit?

31. Short Quiz
Directions: Read each question with understanding.
Write the of the correct answer.
1.What is current measured in?
a.Ω (Ohms)
b.A (Amps)
c. V (Volts)

32. Short Quiz
2. What is resistance measured in?
a.Ω (Ohms)
b.A (Amps)
c. V (Volts)
3. What is Resistance?
a.The flow of electrons
b.Electric potential difference
c. The ability to reduce the flow of electrons

33. Short Quiz
4. The mathematical relationship among Voltage, Current, and
Resistance.
a. Faraday's Law
b. Edison's Law
c. Ohm's Law
5. Current times Resistance equals (I X R).
a. Amperage
b. Voltage
c. Ohm