1. What is Electrical Power?

Electrical power is the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt (W), which equals one joule per second. Power measures how much energy is consumed or produced by an electrical device over time.

2. How Does the Calculator Work?

The calculator uses the electrical power formula:

Where:

• \( P \) — Power in watts (W)
• \( V \) — Voltage in volts (V)
• \( I \) — Current in amperes (A)
• \( PF \) — Power factor (unitless, between 0 and 1)

Explanation: For purely resistive loads (like incandescent bulbs), PF=1. For inductive loads (like motors), PF is typically between 0 and 1.

3. Importance of Power Calculation

Details: Calculating appliance wattage helps determine energy consumption, select proper circuit protection, estimate electricity costs, and ensure electrical system safety.

4. Using the Calculator

Tips: Enter voltage in volts, current in amperes, and power factor (1 for resistive loads, typically 0.8-0.9 for inductive loads). All values must be valid (voltage > 0, current > 0, PF between 0-1).

5. Frequently Asked Questions (FAQ)

Q1: What if I don't know the power factor?
A: For resistive loads (heaters, incandescent lights), use PF=1. For motors, typical values are 0.8-0.9. Check appliance specifications if unsure.

Q2: How does this relate to energy consumption?
A: Energy (kWh) = Power (kW) × Time (hours). Multiply wattage by hours used to estimate energy consumption.

Q3: What's the difference between real power and apparent power?
A: Real power (P, in W) is what performs work. Apparent power (S, in VA) is V×I. The ratio (P/S) is the power factor.

Q4: Why do some appliances have high current but low power?
A: This typically indicates a low power factor, common in inductive loads like motors where current and voltage are out of phase.

Q5: How can I measure voltage and current?
A: Use a multimeter - measure voltage across the appliance and current in series with the circuit (with proper safety precautions).