A spectroscopic instrument can resolve two nearby wavelengths λ and λ + Δλ if λ/Δλ is smaller than 8000. This is used to study the spectral lines of the Balmer series of hydrogen. Approximately how many lines will be resolved by the instrument?
The range of wavelength falling in Balmer series is between 656.3 nm and 365 nm.
It is given that the resolution of the instrument is λ/ (λ + ∆λ) < 8000.
Number of wavelengths in this range will be calculated in the following way:
`(656.3-365)/8000 = 36`
Two lines will be extra for the first and last wavelength.
∴ Total number of lines = 36 + 2 = 38