1. Understanding Electrical Power

Electrical power is the rate at which electrical energy is transferred by an electric circuit. The basic unit of power is the watt (W). Understanding the relationship between power, voltage, and current is fundamental in electrical engineering and electronics.

2. The Power Equation

The fundamental equations relating power, voltage, and current are:

Where:

• \( P \) — Power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)

Explanation: These equations show that power is the product of voltage and current. If you know any two of these values, you can calculate the third.

3. How the Calculator Works

Details: The calculator allows you to compute any one of the three variables (power, voltage, or current) when you know the other two. Simply select what you want to calculate, enter the known values, and click "Calculate".

4. Practical Applications

Examples: This calculation is essential for:

• Determining the power consumption of electrical devices
• Sizing electrical circuits and components
• Calculating battery life
• Designing power supplies

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between watts and amps?
A: Watts measure power (energy per unit time), while amps measure current (charge flow per unit time). Watts = Volts × Amps.

Q2: How do I convert watts to amps?
A: Divide watts by volts (I = P/V). For example, 100W at 12V is 8.33A.

Q3: Why is voltage important in power calculations?
A: Voltage is the "pressure" that drives current. The same power can be achieved with different combinations of voltage and current.

Q4: Can I use this for AC circuits?
A: For simple resistive loads, yes. For reactive loads (motors, transformers), you need to consider power factor.

Q5: What's a typical household circuit rating?
A: In North America, 15A or 20A at 120V (1800W or 2400W maximum).