The luminous flux of a monochromatic source of 1 W is 450 lumen `W^-1`. Find the relative luminosity at the wavelength emitted.

Explanation

To solve the problem, we need to find the relative luminosity of a monochromatic source of light based on the given luminous flux. Here’s the step-by-step solution:

### Step 1: Understand the Given Information
We are given:
- The luminous flux of a monochromatic source of 1 W is 450 lumens per watt.
- The luminous flux for a 555 nm source of 1 W is 685 lumens.

### Step 2: Define Relative Luminosity
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