1. OH MY! Circuits, Batteries Volts, Amps, and Ohms

2. What is a circuit? Circuit – a closed path through which ELECTRONS can flow.  Think a about a race track. Can’t race with out a complete track. We can classify them in two ways.  Open – electrons won’t be moving  Closed – electrons will be moving

3. Marble Analogy

4. Please sketch into your notes!!!

6. Wet and Dry Cell Batteries Diagram from page 602 of Physical science textbook. Figure (A) is a dry cell battery and is a single cell. Figure (B) is a wet cell battery and has multiple cells. When we say cell we mean one cell, when we say battery we mean multiple cells.

7. Wet Cell vs. Dry Cell. How their made. Wet Cell - Lead Acid Battery Dry Cell - Alkali Battery Username waukee4 and password aea11

8. Three Basic Units The three basic units in electricity are:  Voltage (V) (measured in volts)  Potential difference  Current (I) (measured in amps)  Flow or number of electrons  Resistance (R) (measured in ohms)  Tendency to oppose

9. Think Plumbing…(don’t write this!) Voltage would be like water pressure… Current is the flow rate… Resistance is the pipe size...

11. Another Analogy

12. Ohm’s Law! I = V/R  This states that current is equal to the voltage divided by the resistance.  This equation can be re-written to solve for any specific variable

13. Problem… You have a tank filled with water connected to a hose that you are using to water the lawn… What happens if you just increase pressure in the tank? Remember……….. Ohms Law…..

14. Answer… More water will come out of the hose Electricity works in the same way! Increasing the voltage will make more current flow

15. Volt Meter Volt meters are tools used to tell us how much voltage anything is producing…

16. How to use a Volt meter