1. Calculate the wavelength (in nm) of the red light emitted by a barcode scanner

that has a frequency of

4.62 x 1014 5-1.

649.4 nm

6.49 * 10⁻⁷ m (or) 649 nm

Explanation:

Wavelength and Frequency are inversely proportional to each other. Greater the wavelength smaller the frequency and vice versa.

Solution:

The relation between wavelength and frequency is as follow,

υ = c / λ

where

υ = frequency = 4.62 * 10¹⁴ s⁻¹

c = velocity of light = 3.0 * 10⁸ ms⁻¹

λ = wavenumber = ?

Solving above equation for λ.

λ = c / υ

Putting the given values,

λ = 3.0 * 10⁸ ms⁻¹ / 4.62 * 10¹⁴ s⁻¹

Result:

λ = 6.49 * 10⁻⁷ m (or) 649 nm