1. What is Power Efficiency?

Power efficiency measures how effectively a system converts input power into useful output power. It's expressed as a percentage, with higher values indicating more efficient power conversion.

2. How Does the Calculator Work?

The calculator uses the power efficiency formula:

Where:

• \( P \) — Efficiency percentage (%)
• \( Output \) — Useful power output (watts)
• \( Input \) — Total power input (watts)

Explanation: The formula calculates what percentage of input power is converted to useful output power, with 100% representing perfect efficiency (unattainable in practice due to inevitable energy losses).

3. Importance of Efficiency Calculation

Details: Calculating power efficiency helps in evaluating system performance, identifying energy losses, comparing different systems, and improving energy conservation.

4. Using the Calculator

Tips: Enter both output and input power in watts. Both values must be positive numbers. The calculator will compute the efficiency percentage.

5. Frequently Asked Questions (FAQ)

Q1: What is considered good efficiency?
A: It varies by application. For power supplies, >80% is good, >90% is excellent. For motors, >90% is typical for high-efficiency models.

Q2: Can efficiency exceed 100%?
A: No, that would violate energy conservation laws. Any measurement showing >100% indicates measurement error or external energy input not accounted for.

Q3: Why measure in watts?
A: Watts are the standard unit for power (energy per unit time), making them ideal for efficiency calculations that compare input and output rates.

Q4: How does efficiency affect operating costs?
A: Higher efficiency means less wasted energy, resulting in lower electricity costs and often reduced cooling requirements.

Q5: What causes efficiency losses?
A: Common causes include heat dissipation, friction, electrical resistance, magnetic losses, and mechanical vibrations.