oh my! circuits, batteries volts, amps, and ohms
TRANSCRIPT
OH MY!
Circuits, Batteries Volts, Amps, and Ohms
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
Marble Analogy
Please sketch into your notes!!!
Please sketch into your notes!!!
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.
Wet Cell vs. Dry Cell.
How their made.
Wet Cell - Lead Acid Battery
Dry Cell - Alkali Battery
Username waukee4 and password aea11
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
Think Plumbing…(don’t write this!)
Voltage would be like water pressure…
Current is the flow rate…
Resistance is the pipe size...
Another Analogy
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
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…..
Answer…
More water will come out of the hose
Electricity works in the same way! Increasing the voltage will make more current flow
Volt Meter
Volt meters are tools used to tell us how much voltage anything is producing…
How to use a Volt meter