Introduction: Ohm's Law

Picture of Ohm's Law

FIG:--1Ohm's Law deals with the relationship between voltage and current in an ideal conductor. This relationship states that:

The potential difference (voltage) across an ideal conductor is proportional to the current through it.

The constant of proportionality is called the "resistance", R.

Ohm's Law is given by:

V = I R

I = V / R

R = V / I



Here in that we have all units of resisiter,capester and inductor


Circuit for Ohm's law


AndrewW180 (author)2016-04-12

Nice Job explaining this!

Here is another interesting formula we can find.

To find Power P = IxV (in Watts)

Here is an example:

Suppose we want to limit the current flowing through an LED to 10 milliamps.

We are using the 5 volt supply on the Arduino board.

We have a variety of resistors in our parts box.

From a quick mental calculation we can see that for every 100 ohms we will be letting 50 ma through the LED.

So we need something over 400 ohms.

From the yellow circle above let's try a common 470 ohm resistor.

I = 5/470

I = 10.6ma

And by calculating P we can see that the LED is consuming about 53mw


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