4-Electric Circuits 2

Slideshow: DC Circuits and RC circuits 

Textbook: Not well represented in the textbook, but review Ch 16 for DC circuits. 

Objectives: 

• Basically all the stuff from AP Physics 1, but now with capacitors included

  • resistivity depends on substance

  • use Kirchhoff's loop rules and junction rules to predict & test values (like power, potential difference and current) for resistors, capacitors and sources of EMF when changing their arrangement (parallel, series and combo)

  • Use Kirchhoff's rules as part of an explanation of energy and/or charge conservation

  •  Analyze a non-ohmic resistor and internal resistance of a battery

  • Tell how capacitors work differently when first connected, when fully charged and when first connected in a discharging state.

• Test your understanding of how basic series and parallel circuits work with the Crack The Circuit game at UniverseAndMore. 

Equations:

Common Misconceptions

Simple Circuits

• 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.

AC Circuits

• Charges move all the way around a circuit and all the way back.

• Voltage and current remain constant as in DC circuits.

• Energy is not lost in a transformer.

• A step-up transformer gives you something more for less input.

• Transformers can be used to change DC voltages.

• Electrical companies supply the electrons   for your household current.

To Be Continued . . .