1. Aim: How is a Series Circuit different from a Parallel Circuit?
HW: Ohm’s Law WS

2. Review: Why does current not come from a battery? Explain.
What is the amount of charge passing through a bulb in 5 seconds if the current is 2 amperes?
What is the function of a resistor or load in a circuit?

3. Ohm’s Law
Circuits are drawn a certain way for clarity. What variables are involved with a circuit?
V = IR
R-Resistance (Ω-ohms)
V-potential difference (V)
I-Current (A-amps)
12V
Based on the Do Now, how would we draw a circuit?
Bulb acts as resistor! + -
Light bulb

4. Example #1
The voltage supplied to a circuit with a resistance of 100 ohms is 25 volts. How much current will flow in this circuit?

5. Ohm’s Law Rule
Ohm’s Law may only be used if the current “I” and the voltage “V” are experienced by the resistance “R”.
This means we can’t randomly pick a voltage and a resistance from the problem and divide to get current.
We must be sure the voltage we plugged in is actually measured across the resistance we’re considering.

6. Activity-Creating Circuits
Using the materials provided (wires, bulbs and battery) try to create the following:
Create a circuit and light one bulb. Draw and label your final circuit in your notes!
Create a circuit that will light two bulbs. There are two ways to light 2 bulbs. Can you find both?

7. How can we describe a series circuit?
A complete circular current, where the parts are connected one after another. Only ONE path for electrons to take.
What happens if the switch is open or a light bulb goes out?
Are the lights bright or dim? WHY?
Should Christmas lights be set up in a series circuit?
Include proper way to draw this circuit on board.

8. How can we describe a parallel circuit?
Parallel Circuit – In a parallel circuit, the current can follow more than one path. If the lamps were connected in different paths, one lamp would not stop working if the other lamp went out. Because the electricity could follow different paths, electric current could still reach the other lamp.
Separate pathways are setup. In a parallel circuit, there are several paths for the electrons to take.
What happens if I turn off light A?
Are the lights bright or dim? WHY?
Should Christmas lights be set up as parallel circuits? Why or why not?

9. How do we measure Potential Difference and Current?
Measure Potential Difference with a Voltmeter.
Measured in parallel (Volts-V)
Measure Current with an ammeter.
Measured in series (Amps-A) V
Based on the Do Now, how would we draw a circuit? + -
Light bulb A

10. Summary What provides potential difference in a circuit?
What is the unit for voltage?
What provides resistance?
What are the units and symbol for current?
Describe how electron flow in both a parallel and series circuit.