electricity main concepts

1. “The world looks so different
after learning science.”
Richard Feynman

2. OBJECTIVES
By the end of the session students will
be able to:
• draw electric circuit diagrams.
• State the relationship between voltage,
current and resistance.
• Apply ohm’s law in solving problems.
• Create a simple electric circuit using:
battery, wires and a small lamp in15
minutes.

3. Think-Pair-Share
 Look at the diagrams below:
 What are needed for these
appliances to operate?
 Could you think of similar
appliances used for the same
purpose in olden days?
You got 2
minutes
to share
with
someone
beside/
you

4. Electrical Appliances
 All require electricity to work
 Vacuum cleaner (electricity to
kinetic energy)
 Lamp (electricity to light energy)
 Fan (electricity to kinetic energy)

5. Electrical Appliances
 Now we cannot live without
electricity.
 So many appliances and items
we used require electricity

6. What is electricity?
• Electricity is a form of energy.
• It can be change to other forms.
• Electricity produced by the movement of electrons.
• the movement of electrons makes the:

7. Electrical current
The electrical current is the movement of (electrons) through a
conductor (electrical wire, metal foil, etc.).
the current flows from the point where the electrical potential is highest
to the point where it is lowest.(potential difference)

8. Electrical circuit
 An electric current flows
only when there is:
1. a source of
electrical energy.
2. a closed circuit.

9. Electrical Circuit
simple circuit includes :
A force that pushes the
current(charges) through the circuit.
Voltage Volts (V)
The actual “substance” that is flowing
through the wires of the circuit
(electrons!).
Current(I) Amps(A)
Friction that impedes flow of current
through the circuit .
Resistance Ohms(Ω)

10. In complete
circuit
No battery
Complete
circuit

11. circuit diagram
cell switch wires
Scientists usually draw electric circuits using symbols;

12. Ohm’s Law
Georg Simon Ohm (1787-1854)
the relationship between voltage (V),
current (I) and resistance (R) is
known as :
I = V / R
According to Ohm’s law : At constant
temperature, the current flowing
through a conductor is directly
proportional to the potential difference
across its end.

13. Ohm’s Law Chart
V
I Rx
Cover the quantity that is unknown.
Solve for V
V=IR

14. V
I R
I=V/R
Ohm’s Law Chart
Cover the quantity that is unknown.
Solve for I

15. V
I R
R=V/I
Ohm’s Law Chart
Cover the quantity that is unknown.
Solve for R

16. Work sheet:
• From the next slide answer the question
• You are going to work in 4 teams of 3
students each.
• Write your answers in one sheet for each
group.
• We have 5 minutes to run the activity.

17. The flashlight shown uses a 6 volt battery
and has a bulb with a resistance of 150 .
When the flashlight is on, how much
current will be drawn from the battery?
VT =
+
-
VR
IR
Schematic Diagram
mA40A0.04
150
V6
R
V
I R
R



V
I R

18. Home work(project)
• Using battery, wires and a small lamp
Create a simple electric circuit .

19. Thank you