1. Topic 5.2 Electric Circuits
Electric Currents
Topic 5.2 Electric Circuits

2. Simple Circuit e.m.f. = Electromotive Force
What’s providing the energy? What’s “moving” in the circuit? What’s causing the movement?
e.m.f. =
Electromotive Force
not a force, but the potential difference in volts

3. ElectroMotive Force (EMF)

4. Circuits
If the potential difference of the light bulb is 12V, what is the potential difference of the source in theory? What voltage would we measure in a lab? Internal Resistance is always present!

5. Resistors What does it mean for 2 resistors to be connected:
In Series?
In Parallel?
Do you remember Kirchoff’s Laws?

6. Kirchoff’s Laws
Conservation of Energy
Conservation of Charge

7. Ohm’s Law + Kirchoff’s Laws = Equivalent Resistance in Series

8. Ohm’s Law + Kirchoff’s Laws = Equivalent Resistance in Series

9. Ohm’s Law + Kirchoff’s Laws = Equivalent Resistance in PARALLEL

10. Ohm’s Law + Kirchoff’s Laws = Equivalent Resistance in PARALLEL

11. Potential Divider
What happens to the Vout reading if you change R1?

12. Deriving the Formula

13. Two Cells in Series
More “Voltage”

14. Two Cells in Parallel
Same “Voltage”

15. Escalator Temporarily Out Of Order…
Does not exist!
Escalator Temporarily Stairs
Sorry for the inconvenience
-Mitch Hedberg

16. Two Cells in Series
No “Voltage”

17. Two Cells in Parallel
Same “Voltage” What’s changed?

18. INTERNAL RESISTANCE