The 630-nm light from a helium-neon laser irradiates a grating. The light then falls on a screen where the first bright spot is separated from the central maximum by 0.61 m. Light of another wavelength produces its first bright spot 0.45 m from its central maximum. Determine the second wavelength.

464.8 nm

Explanation:

The second wavelength of light can be calculated using the next equation:

Where:

λ : is the wavelength of light

x: is the distance from the central maximum

d: is the distance between the spots                      

L: is the lenght from the screen to the bright spot

For the first wavelength of light we have:

 (1)    

For the second wavelength of light we have:

  (2)  

By entering equation (1) into equation (2) we have:

Therefore, the second wavelength is 464.8 nm

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