"Explore the fascinating world of electrostatics in this PowerPoint presentation, delving into the principles of static electricity, Coulomb's Law, and practical applications, unraveling the mysteries of charged particles and their dynamic interactions."

1. ELECTROSTATICS
Science, Technology, Engineering, and
Mathematics 12
Chapter 1: Electricity
Prepared by: Lord William B. Pacurib
DON BOSCO TECHNICAL INSTITUTE OF VICTORIAS INC.
VICMICO, Victorias City, 6119 Negros Occidental, Philippines
Senior High School Department | Academic Year 2022–2023

2. OBJECTIVES
• Describe using a diagram charging by
rubbing and charging by induction
• State that there are positive and negative
charges, and that charge is measured in
coulombs
• Calculate the net electric force on a point
charge exerted by a system of point
charges.
• Describe an electric field as a region in
which an electric charge experiences a force
• Use in calculations the relationship
between the electric field and the electric
force on a test charge

3. RULES
1. Refrain from talking if the teacher is
having his lecture. Talk only if you are
called.
2. Quietly remain on your seats while the
class is ongoing (do not roam around the
room).
3. Render appropriate courtesy towards the
teacher.
4. Standard handbook rules apply.
5. Violation of aforementioned rules will be
reflected on the violator’s diary.

4. INTRODUCTION
Electrostatics is the branch of physics that
studies the interactions between stationary
electric charges. It primarily focuses on the
behavior of electric fields and potential in
the absence of moving charges or currents.

5. LESSON PROPER
A. Electric Charge and Static
Electricity
The build-up of electric charge
on the surface on an object is
called static electricity.
The effects of static electricity
are explained by a physical
quantity called electric
charge.

6. LESSON PROPER
A. Electric Charge and Static
Electricity
• There are only two types of charge,
one called positive and the other
negative.
• It is also conventionally known that
like charges repel, and unlike
charges attract.
• The force between charges
decreases with distance.

7. LESSON PROPER
B. Conductors and Insulators
Conductors allow charges to move
through them with relative ease.
• The electrons in some metals and
similar conductors are not bound to
individual atoms or sites in the
material.
• These free electrons are free to
move away from its atomic orbit
and can move through materials.

8. LESSON PROPER
B. Conductors and Insulators
On the other hand, some substances, do not allow charges to move
through them. These materials that can hold electrons securely within
their atomic orbits are called insulators.

9. LESSON PROPER
B. Conductors and Insulators
In general, good conductors of
electricity (metals like copper,
aluminum, gold, and silver) are also
good heat conductors, whereas
insulators of electricity (wood, plastic,
and rubber) are poor heat conductors.

10. LESSON PROPER
C. Charging by Conduction and
Induction
This frictional contact leads to one
material gaining electrons and
becoming negatively charged,
while the other loses electrons
and becomes positively charged.
Charging by rubbing, also known as triboelectric charging,
occurs when two different materials are rubbed together, causing the
transfer of electrons between them.

11. LESSON PROPER
C. Charging by Conduction and
Induction
This occurs when a charged
object, such as a negatively
charged rod, induces a
temporary separation of
charges in a neutral object,
resulting in one side becoming
positively charged and the other
side negatively charged.
Meanwhile, charging by induction is a process where an object
becomes charged without direct contact with a charged object.

12. LESSON PROPER
D. Coulomb’s Law
The mathematical formula to calculate
the electrostatic force vector between
two charged particles is called
Coulomb’s law, named after the French
physicist Charles Coulomb (1736-
1806). Coulomb was the first to propose
a formula to calculate the electrostatic
force.

13. LESSON PROPER
D. Coulomb’s Law
where F is the force between two point
charges q1 and q2 separated by a distance
r; k is a constant that is equal to 8.99 ×
10^9 Nm^2/C^2
𝐹 = 𝑘
𝑞1𝑞2
𝑟2
It is mathematically expressed as:

14. LESSON PROPER
D. Coulomb’s Law
The electrostatic force (also called the
Coulomb force) is defined as the amount
and direction of attraction or repulsion
between two charged bodies. It is a
vector quantity and is expressed in units
of Newtons.

15. LESSON PROPER
D. Coulomb’s Law

16. LESSON PROPER
D. Coulomb’s Law

17. LESSON PROPER
D. Coulomb’s Law
Now, let solve a problem.
SAMPLE PROBLEM 1: Let's assume
two charges, q1 =2 μC and q2 =−3 μC,
are separated by a distance r = 0.1 m.
Find its electrostatic force.

18. LESSON PROPER
E. The Electric Field
The electric field E is a vector field that
describes the force experienced by a
charged particle at any given point in
space.
It is defined as the force per unit charge
and is measured in Newtons per
Coulomb (N/C).

19. LESSON PROPER
E. The Electric Field
It is mathematically defined as:
𝐸 =
𝐹
𝑞
where F is the Coulomb or electrostatic
force exerted on a small test charge q

20. LESSON PROPER
E. The Electric Field
On the other hand, the magnitude of the
electric field E created by a point charge
Q is mathematically expressed as
follows:
𝐸 = 𝑘
𝑄
𝑟2

21. LESSON PROPER
E. The Electric Field
In the context of the electric field, q and
Q represent different quantities:
• q typically denotes a point charge,
and it is used to represent the
magnitude of the charge at a specific
location. It can be either positive or
negative.
• Q is often used to represent the total
charge of an object or a system of
charges. It encompasses the sum of all
the individual charges within that
system.

22. LESSON PROPER
E. The Electric Field
Now, let’s solve a problem.
SAMPLE PROBLEM 2: Calculate the
strength of the electric field E due to a
total charge of 2.00 nC at a distance of
5.00 mm from the charge.
SAMPLE PROBLEM 3: What force
does the electric field found in Sample
Problem 2 exert on a point charge of -
0.250 μC?