oh my! circuits, batteries volts, amps, and ohms

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