Power in electrical circuits can seem a little confusing at first, but once you understand the basics, it gets much simpler. Let's break it down by looking at how to calculate power in two different types of circuits: series circuits and parallel circuits.

1. Series Circuits:

In a series circuit, all the parts are connected one after the other. This means the same electric flow, called current, goes through each part.

To find power in a series circuit, we use this formula:

P = I² R

Where:

• P is the power measured in watts (W),
• I is the current measured in amperes (A), and
• R is the total resistance measured in ohms (Ω).

Since the same current flows through all parts, you can find the total resistance by adding up the resistance of each part:

R_total = R₁ + R₂ + R₃ + ...

Once you have the total resistance and the current, put those numbers into the power formula.

2. Parallel Circuits:

Parallel circuits are a bit different. In these circuits, each part is directly connected to the power source. This means that each part can have a different current, but the voltage, or electrical pressure, is the same for all parts.

To calculate power in a parallel circuit, we use this formula:

P = V I

Where:

• V is the voltage measured in volts (V),
• I is the total current flowing through the circuit.

To find the total current in a parallel circuit, add up the currents from each path:

I_total = I₁ + I₂ + I₃ + ...

You can also use another way to calculate power with resistance by using Ohm's law, which tells us that V = IR.

In summary, calculating power in circuits depends on knowing either the voltage and current or the resistance.

Just remember:

• In series circuits, the current stays the same.
• In parallel circuits, the voltage stays the same!

Once you remember these points, power calculations become much easier!