1. What is the Watts Formula?

The Watts formula calculates real power in an AC circuit by multiplying the root mean square (RMS) voltage, RMS current, and the power factor (cos φ). It provides the actual power consumed by the load.

2. How Does the Calculator Work?

The calculator uses the Watts formula:

Where:

• \( W \) — Real power in watts
• \( V_{rms} \) — Root mean square voltage
• \( I_{rms} \) — Root mean square current
• \( \cos \phi \) — Power factor (0 to 1)

Explanation: The formula accounts for both the magnitude of voltage and current and their phase relationship through the power factor.

3. Importance of Power Calculation

Details: Accurate power calculation is crucial for electrical system design, energy efficiency assessment, and proper sizing of electrical components.

4. Using the Calculator

Tips: Enter RMS voltage in volts, RMS current in amps, and power factor (between 0 and 1). For DC circuits, use power factor of 1.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between real power and apparent power?
A: Real power (W) is the actual power consumed, while apparent power (VA) is the product of V_rms and I_rms without power factor.

Q2: What is a typical power factor value?
A: For resistive loads it's 1.0, for inductive loads (motors) typically 0.8-0.9, and for heavily inductive loads can be as low as 0.3.

Q3: How is RMS different from peak voltage?
A: RMS voltage is the equivalent DC voltage that would deliver the same power. For sine waves, RMS = Peak/√2.

Q4: Can this formula be used for DC circuits?
A: Yes, for DC simply set power factor to 1 (since there's no phase difference in DC).

Q5: Why is power factor important?
A: Low power factor means higher current is needed to deliver the same real power, increasing energy losses in distribution systems.