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Light Power Formula:
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Light power refers to the total radiant energy emitted, transmitted, or received per unit time by a light source. It represents the actual energy output of a light source and is measured in watts (W).
The calculator uses the fundamental physics formula:
Where:
Explanation: This formula calculates the total power by multiplying the intensity (power per unit area) by the total area over which the light is distributed.
Details: Calculating light power is essential for designing lighting systems, determining energy consumption, optimizing illumination efficiency, and ensuring proper lighting conditions for various applications.
Tips: Enter intensity in W/m² and area in m². Both values must be positive numbers. The calculator will compute the total power in watts.
Q1: What is the difference between light power and light intensity?
A: Light power (P) is the total energy output, while light intensity (I) is the power per unit area. Power is measured in watts, intensity in watts per square meter.
Q2: How is this different from luminous power?
A: Light power refers to radiant power (total energy), while luminous power considers the human eye's sensitivity to different wavelengths and is measured in lumens.
Q3: What are typical intensity values for common light sources?
A: Direct sunlight: ~1000 W/m², office lighting: ~0.01-0.1 W/m², moonlight: ~0.001 W/m².
Q4: Can this formula be used for all types of electromagnetic radiation?
A: Yes, this fundamental relationship applies to all electromagnetic radiation, not just visible light.
Q5: How does distance affect light power calculation?
A: Distance affects intensity (inverse square law), but the total power remains constant in a lossless system. For distant sources, you need to account for the spherical area.