Ohm's Law

Ohm's Law for the Beginner:

There's no getting away from it, electronics, even at the hobbyist level, requires a bit of maths now and again. One of the fundamental formulae that you will encounter all the time is Ohm's Law. This shows the relationship between voltage, current and resistance.

Imagine a garden hose.

• Water pressure is like voltage. It's the force pushing the water through the hose.
• Water flow is like current. It's the amount of water flowing through the hose.
• Hose size is like resistance. A smaller hose (higher resistance) will allow less water to flow, even with the same water pressure.

Ohm's Law is a simple relationship between these three things:

• If you increase the voltage (pressure), you'll increase the current (flow).
• If you increase the resistance (smaller hose), you'll decrease the current (flow).

So, the formula for Ohm's Law is:

• Voltage = Current x Resistance

Or, in symbols:

• V = I x R

This means that if you know any two of these values, you can calculate the third.

For example, if you know the voltage and the resistance in a circuit, you can calculate the current.

If you are looking for resistors to include in your project, check out the Bitsbox resistor section.