Higher Physics Lab Atomic & Nuclear Physics



Exp-1 To determine the wavelengths of Balmer series in the visible region from hydrogen emission.
Exp-2 To determine the Rydberg constant.

  • High quality imported grating (100,300,600 line/mm).
  • Electrical safety tested high voltage power supply with overload current protection.
  • Tube filed with research-grade gasses & vapors.
  • Bohr atomic model.
  • Visible spectrum.
  • Energy level.
  • Rydberg atom.
  • Rydberg's constant.

Principle and Working:
Hydrogen atoms in a discharge lamp emit a series of lines in the visible part of the spectrum. This series is called the Balmer series which continues into the ultraviolet range. Rydberg generalized the Balmer’s formula in terms of wave numbers to describe wavelengths of spectral lines of many chemical elements. For hydrogen the Balmer’s formula becomes a special case of Rydberg’s formula and is given by

1/λ=R(1/22 - 1/n2)

where n are integers, 3, 4, 5, … up to infinity and
R is Rydberg constant ( R = 4/B where B is the Balmer’s constant). In the present setup, the spectral lines of hydrogen is observed by means of diffraction grating. The wavelength of the visible lines of Balmer series of hydrogen are measured by spectrometry.


Cat. No. Item Name SK043 SK062
SL806 Spectrometer (L.C. = 20 sec) 1  
SL745 Diffraction grating 1 1
SW281 Spectrum tube power supply 1 1
SN631 Hydrogen tube 1 1
SE080 Power supply 12V AC/DC   1
SN583 Spectrometer and Goniometer   1
R1437 Allen key 1  

* Note: SK062 only manufactured against order.

Atomic & Nuclear Physics Experiments