Basic Electromagnetic Exercise: Ohm Law

This is a very basic project that allows to experiment the (very) basics of circuitry construction and Ohm's Law. The project consist in getting a LED light on by using the principles of Current, Voltage and Resistance.

For this project i used:

1. A 9V Battery

2. Resistances

3. A 20mA LED light 

4. A multimeter or VOM

First i started by measuring the (real) voltage of the battery and the resistances.

Then proceded to calculate the resistance need of the circuit by using the equation of Ohm's Law.

I had a 20mA LED light that needed to be turn on with a 9V battery and proceded to calculate the amount of resistance required to get the light going.

This is where the ohm law gets in handy: We had two of the variables of the equation (voltage and current), giving us the way to calculate the missing one (resistance) in order to get the LED going.

Thus:

R=V/I

R=9.5/0.020

R= 475 ohms

So we needed a total resistance of 475 ohms, and had some resistances with a value of 100 ohms. For this matter i divided the resistance required to decide the quantity of resistance needed.

Then  connected the components in the following way:

• Led anode to battery anode
  
• Led cathode to resistances
  
• Resistances to battery cathode
  

And Voilá. We turned the LED using the basics of circuitry and ohm law.