# U10-Electric Circuits

**Slideshow **found here: Circuits Notes

**Textbook**: Chapter 16 in Mastering Physics (get online code for registration on about page of google classroom)

**Basic Video tutorials** from Dan Fulelrton: https://www.youtube.com/playlist?list=PLd2HWlWc-MszmgWIKnYCtN_3Heo1qroBi

**Worked examples and concept tutorials** from Mrs. Twu: https://sites.google.com/site/twuphysicslessons/home/circuits

### Essential Knowledge:

Essential Knowledge:

- ΔV=change in electrical potential energy per charge moving through a circuit
- ΣΔV=0 is used to explain conservation of energy in a circuit.
- ΔV=IR can be used to find ΔV for a single resistor using values of I and R for the resistor or for the overall circuit using the total I and equivalent resistance.
- Power is a rate of energy transfer and found using P=IV=ΔE/t. Individual resistors use energy (produce heat) as current runs through them.
- Charge flow is conserved in a closed system. This is demonstrated by the junction rule, where the sum of currents flowing into a circuit equal the sum of currents flowing of of a circuit.

### Student Objectives:

Student Objectives:

- Use circuit diagrams or descriptions to perform calculations of unknown values of current in different branches in a circuit.
- Kirchhoff's junction rule (ΣI
_{in}= ΣI_{out})- Make claims and predictions about simple circuits based on conservation of charge.
- Compare currents in parallel branches using the junction rule/conservation of charge
- In particular, be prepared to discuss what would happen to branches if configurations are changed (double a resistor's value, open a switch, add a parallel path, etc)

- Design an experiment to show that charge is conserved in a parallel circuit. Plan data collection and analysis.

- Kirchhoff's loop rule (ΣΔV=0)
- construct or interpret a graph of energy changes within an electrical circuit
- design an experiment to demonstrate the validity of Kirchhoff's loop rule.
- consider how you would use a voltmeter on several components in series or possibly a simple combination circuit.

- Perform calculations using conservation of energy (loop rule)

### Equations:

Equations:

### Common Misconceptions: (these statements all have errors)

Common Misconceptions: (these statements all have errors)

- Resistors consume charge.
- Electrons move quickly (near the speed of light) through a circuit.
- Charges slow down as they go through a resistor.
- Current is the same thing as voltage.
- There is no current between the terminals of a battery.
- The bigger the container, the larger the resistance.
- A circuit does not have form a closed loop for current to flow.
- Current gets "used up" as it flows through a circuit.
- A conductor has no resistance.
- The resistance of a parallel combination is larger than the largest resistance.
- Current is an excess charge.
- Charges that flow in circuit are from the battery.
- The bigger the battery, the more voltage.
- Power and energy are the same thing.
- Batteries create energy out of nothing.