The wavelength range of the visiblespectrum extends from violet (400 n

1.	The wavelength range of the visiblespectrum extends from violet (400 nm)to red (750 nm). Express thesewavelengths in frequencies (Hz)(1nm 10-9 m)
Answer» We know that v=λf where v is velocity,λ is wavelength and f is frequency. Range of spectrum is 400 nm to 750 nm which equals 400 nm=4×10⁻⁷ m750 nm=7.510⁻⁷m Here v=c=310⁸ m/s So, Upperlimit v=λf∴310⁸=410⁻⁷f∴f=310⁸/410⁻⁷∴f=0.7510¹⁵So f=7.510¹⁴ Hz Similarly The lower limit will be410¹⁴Hz Thus the range of spectrum in frequency is 410¹⁴ Hz-7.510¹⁴ Hz

The wavelength range of the visiblespectrum extends from violet (400 nm)to red (750 nm). Express thesewavelengths in frequencies (Hz)(1nm 10-9 m)

Answer»

We know that v=λf where v is velocity,λ is wavelength and f is frequency.

Range of spectrum is 400 nm to 750 nm which equals

400 nm=4×10⁻⁷ m750 nm=7.5*10⁻⁷m

Here v=c=3*10⁸ m/s

So, Upperlimit

v=λf∴3*10⁸=4*10⁻⁷*f∴f=3*10⁸/4*10⁻⁷∴f=0.75*10¹⁵So f=7.5*10¹⁴ Hz

Similarly The lower limit will be4*10¹⁴Hz

Thus the range of spectrum in frequency is 4*10¹⁴ Hz-7.5*10¹⁴ Hz