Apologia Physics: Electrical Circuits (and demonstrating with Snap Circuits)

Students need to be familiar with various terms and calculations that relate to electrical circuits. They should be able to define VOLT, AMP, conductor, switch, resistor, capacitor, fuse, circuit breaker, series and parallel circuits. They should be able to explain how a battery stores and releases energy.

Electrical circuit: manages the flow of electrons by shaping the conductor (often copper wire) and controlling the electrical field.
Volts: electrical potential
Lead acid batteries, common in cars, use an Oxidation/Reduction reacting to create electrical current.  LEO the lion says GER.  Loss if Electrons Oxidation, Gain of Electrons Reduction.
Resistance: how a conductor impedes the flow of electrons.  Electrical heating devices use resistance in wires to create heat.  For example, toaster, coffee maker, electric stove.  There is resistance in all electric lines.
If resistors are in series the total resistance is the sum of the resistance in the resistors.
If the resistors are in parallel, the total resistance is 1/Rt=1/R1 + 1/R2  Therefore if two resisters (10 ohms ad 20 ohms) are in series the total resistance is 30 ohms.  If they are in parallel, the total is 6.7 ohms.  Go ahead and prove the math!


We demonstrated much of this with Snap Circuits.  Each student was instructed to put together a number of circuits which used a switch, resistor ( and demonstrate to me the resistor worked ), rheostat ( a variable resistor ), sound device, light bulb, fan, etc.  Also put together circuits which demonstrated how a series and parallel circuit worked.  Each demonstration was then supported by a drawing in which the students had to use the correct symbol for the various electrical devices.

We discussed personal situations which demonstrated how fuses and circuit breakers worked in their houses.  Older houses very often do not have enough power in their wiring that you can run your coffee machine and your toaster at the same time in the same  room.  You have to find an outlet on a different circuit to run the toaster if you have already started your coffee pot!  Do not under any circumstances replace a fuse with a penny so that you can get more power to an appliance; good way to start a fire.    There are various levels of power (amperage) in various circuits running in your house.  Obviously it takes more power to run your kitchen than your bedroom.  It takes more power to run your washing machine or your HVAC than your television, etc.