Question

A barcode scanner emits a red light with frequency of 4.62x1014 s –1 . What is the wavelength of this light in nm?

Answer 1

Answer:

 λ = 649 nm

Explanation:

given,                                    

frequency,f = 4.62 x 10¹⁴ Hz

speed of light,c = 3 x 10⁸ m/s

we know,                                      

c  = f λ                                                          

$\lambda=\dfrac{c}{f}$                        

$\lambda=\dfrac{3\times 10^8}{4.62\times 10^{14}}$

 λ = 6.4935 x 10⁻⁷ m

 λ = 649 x 10⁻⁹ m

 λ = 649 nm

the wavelength of this light is equal to 649 nm