The document discusses the relationships between current, voltage, and resistance according to Ohm's Law. It provides examples of applying Ohm's Law to calculate values in different circuit scenarios, such as calculating current given voltage and resistance. It also explains key concepts, including that resistance remains constant for a material, and that increases in voltage correspond to increases in current. The document aims to illustrate how Ohm's Law can be used to analyze electrical circuits.

1. CURRENT, VOLTAGE and
RESISTANCE: The irRe latio nships
OHM’s LAWA light bulb in a circuit can be lighted
dim or very bright. For a circuit like
this, many factors must be considered
to best describe what might had
happened on the light bulb.
Several answers will clearly

2. CURRENT, VOLTAGE AND
RESISTANCE… Their Relationships
When comparing the brightness of
the bulb in each case. There
noticeable difference in each of the
Case to inve stig ate …
Case
1
Case
2
Case
3

3. CURRENT, VOLTAGE AND
RESISTANCE… Their RelationshipsAn important generalization that
can be made from the three (3)
cases is that, the number of dry
cells increases, the brightness of
the bulb also increases.
The dry cells in the setup provided
the emf that maintained the voltage
across the light bulb. With this, we
can associate the increase in the

4. CURRENT, VOLTAGE AND
RESISTANCE… Their Relationships
The activity simply shows the
concepts of the effect of voltage,
electric current to each other.
“An increase in the voltage on the
bulb results in an increase in
electric current through the bulb.”
In 1837, Georg Simon Ohm
discovered the relationship

5. CURRENT, VOLTAGE AND
RESISTANCE… Their RelationshipsOhm’s law states that “the ratio of
voltage to current is constant
known as resistance”.
The law can be illustrated and
plotted into a graph of VOLTAGE-
versus-CURRENT.
V α I (sim ply m e an that Vis dire ctly
pro po rtio nalto I)
V
I
V
I
--- = R (constant)R (constant)

6. CURRENT, VOLTAGE AND
RESISTANCE… Their Relationships
Resistance is the property of the
wire that is not affected by voltage
nor current through the wire.
The unit o f re sistance is equal to Volt
per Ampere. The unit V/A is
equivalent to the unit Ohm
(re pre se nte d by the Gre e k le tte r o m e g a,
Ω) in the honor of Georg Simon
Ohm.

7. CURRENT, VOLTAGE AND
RESISTANCE… Their Relationships
Let’s apply Ohm’s Law to a
practical example.
A hot plate of an electric stove
draws a current of 5A when
plugged to a 220V source. What is
the resistance of the hot plate?
To compute…
I = 5A V = 220V R = ?

8. CURRENT, VOLTAGE AND
RESISTANCE… Their Relationships
Ohm’s Law applied to another
practical example.
What is the current in the circuit
which consists of a 12V energy
source and a load of 9 ohms?
To compute…
R = 9Ω V = 12V I = ?

9. CURRENT, VOLTAGE AND
RESISTANCE… Their Relationships
Ohm’s Law applied to another
practical example.
A resistor is connected to a 6-
Volts battery. The ammeter in the
circuit reads 2A. What is the value
of the resistance?
To compute…
V = 6V I = 2A R = ?

10. CURRENT, VOLTAGE AND
RESISTANCE… Their Relationships
Ohm’s Law applied to another
practical example.
An electric iron rated 220V has a
resistance of 60Ω. Calculate the
current through it when it is
connected to a wall socket and
switched on?
To compute…

11. CURRENT, VOLTAGE AND
RESISTANCE… Their RelationshipsSolve the worded problem in ¼ by
following the standard format.
Required items: given, unknown,
formula & solving.
A resistance of 18 ohms is across
a 3-V battery. What is the current
in the circuit?
To co m pute …
R = 18Ω V = 3V I = ?

12. CURRENT, VOLTAGE AND
RESISTANCE… Their RelationshipsTo use Ohm’s Law, one must
remember the effect of each
quantity present in the circuit.
Another important item is the
formula/equation.
The equation can be associated to
a triangular formula as used also
in the format in the Newton’s 2nd
Law.
V
RI