1. CH 5 – Electricity and Magnetism
Electrical Circuits
CH 5 – Electricity and Magnetism

2. Ohm’s Law
V = IR V: I: R:

4. Resistors in Circuits
Series
Parallel

5. Resistance and Conductance
A resistor resists (slows down or stops) the flow of electrons. Insulators are resistors.
Ex: Plastic, glass, ceramic, tungsten, wood, distilled water (water with no electrolytes)
Conductors conduct (allow for) the flow of electrons.
Ex: Metals (copper, gold, etc.), acidic and basic solutions, salt water, (water with electrolytes)
A good conductor is a poor resistor and a good resistor is a poor conductor

6. Factors that affect resistance and conductance
Type of wire: different types of material conduct electrons better
Metal wire (gold is best, copper is cheap and good)
Non-metal material (wouldn’t conduct)

7. Factors that affect resistance and conductance
Length of wire: longer wire = more distance resisting electron flow
Short wire
Long material

8. Factors that affect resistance and conductance
Diameter of wire: wider and larger wires conduct better
Thick wire
Thin wire

9. Factors that affect resistance and conductance
Temperature of wire: the hotter the wire, the more resistance there is
Cold wire
Hot wire

10. So the best wire would be…
Metal (gold), short, thick, cold

12. Finding the resistance when resistance graph is given.

15. Finding resistance when conductance graph is given.

18. Finding resistance when a table is given.