2. Learning Objective
At the end of this lesson, the learner should be able to
describe what voltage, current and resistance are.
3. Have you ever wondered
what the world would be like
without electricity?
All the things that we enjoy
now will not be possible
without it.
4. In this activity, you will observe how static electricity behaves.
Take a look at the paper bits that dances on top of a plastic
cover.
Dancing Paper Bits
5. Learn about It
• Work is required to push a charged particle.
• The work required to move a particular particle against the
electric force is equal to EPE.
Electric Potential Energy (EPE)
6. Learn about It
• Electric potential is measured in volts (V). Hence, it is often
called voltage (V). Mathematically, electric potential is defined
in the equation below.
Electric Potential and Voltage
7. Learn about It
• The EPE of a charged object is also changed when work is
done to move the charge from one point to another.
Electric Potential Difference
8. Learn about It
• There is a difference in the electric potential energy of the
charged particle from point A to point B.
Electric Potential Difference
9. Learn about It
• Voltage pushes the electric charges to move from one point to
another.
• Charges cannot flow if there is potential difference.
Voltage (V)
10. Learn about It
Cell is a device used to produce amount of voltage
needed by a material. A group of cells is called a
battery.
The Philippine voltage rating is 220 V. This is the
voltage of our sockets at home.
11. Learn about It
• When objects with different voltage are connected and there is
potential difference between them, this make charges flow from
one end to another.
• In simplest terms, it is the flow of charge.
Electric Current (I)
12. Learn about It
• Current is mathematically defined as
where
I is current in amperes (A),
q is the number of charges passing through the wire in coulomb, and
t is the time it takes for the charges to pass an area in the wire in
seconds (s).
Electric Current (I)
13. Try It!
An electric wire is passed by 100 coulombs of
electric charges in 50 seconds. Calculate the
current in the wire.
14. Try it (Answer)
An electric wire is passed by 100 coulombs of electric
charges in 50 seconds. Calculate the current in the wire.
The current in the wire is 2 A.
15. Try It!
A conductor has a current of 0.5 A. How many
coulombs of electric charges will pass through it in
5 seconds?
16. Try it (Answer)
A conductor has a current of 0.5 A. How many coulombs of
electric charges will pass through it in 5 seconds?
The number of charges passing through the wire is 2.5
C.
17. Learn about It
• Resistance impedes the flow of charge.
• It is a quantity that restricts current. It is measured in ohms (Ω),
and is denoted as R.
• The greater the resistance, the harder the current will flow.
• This could result to more waste energy.
Resistance
18. Learn about It
Conductor
• materials in which charge can flow easily
Insulator
• materials which prevents the flow of charges
Resistance
19. Check Your Understanding
Read and analyze the following statements given. Determine
the electrical quantity (current, voltage or resistance)
described by each statement.
1. It refers to the flow of electrical charges across a conductor.
2. It has a unit of ohm which is named after George Simon Ohm.
3. It is the property of a conductor to resist the flow of its electrical
charges.
20. Check Your Understanding
4. It refers to the amount of force needed to make the electrical
charges flow in a conductor.
5. It is the number of charges passing through a conductor per
unit time.
Read and analyze the following statements given. Determine
the electrical quantity (current, voltage or resistance)
described by each statement.
22. Learning Objective
At the end of this lesson, the learner should be able to
infer the relationship between current, voltage, and
resistance.
23. We all now know that in order
for our appliances and
gadgets to function, potential
differences must be applied.
24. Learn about It
• It summarizes the relation among the current, voltage, and
resistance.
• The current is directly proportional to the voltage and
inversely proportional to the resistance.
• If the resistance of a circuit is constant, then the current and
the voltage are proportional.
Ohm’s Law
25. Learn about It
• As the voltage increases, the current also increases.
• If the voltage of a circuit is constant, a greater resistance would
mean less current.
Ohm’s Law
26. Learn about It
Mathematically, Ohm’s law is stated as
Ohm’s Law
where
V is voltage in Volts (V),
I is current in amperes (A), and
R is resistance in ohms (Ω).
27. Learn about It
Ohm’s Law Magic Triangle
Cover the quantity that you will be
looking for and the remaining two
variables will be used for solving
what is missing.
28. Try It!
A circuit has a resistance of 90 Ω. What is the
voltage across the circuit if the current is 1.2 A?
29. Try It! (Answer)
A circuit has a resistance of 90 Ω. What is the
voltage across the circuit if the current is 1.2 A?
30. Try It!
A light bulb has a resistance of 60 Ω. How much
current does it draw when a voltage of 24 V is
applied across it?
31. Try It! (Answer)
A light bulb has a resistance of 60 Ω. How much
current does it draw when a voltage of 24 V is
applied across it?
32. Try It!
A conductor has a voltage reading of 80 V across
it. If the current in the conductor is 180 mA,
calculate its resistance.
33. Try It! (Answer)
A conductor has a voltage reading of 80 V across
it. If the current in the conductor is 180 mA,
calculate its resistance.
34. Check Your Understanding
Read and analyze the following statements given.
Determine the possible trend of the electrical
quantity in each of the following items.
1. If current increases, resistance will ________________.
2. If voltage decreases, current will __________________.
3. If resistance increases, current will _________________.
4. If voltage increases, current will ____________________.
5. If current decreases, resistance will ________________.
