Wednesday, 17 September 2014


1. Derive the expression Bohr’s radius.
2. Derive the expression velocity of electron in nth orbit.
3. Derive the expression energy of the electron in  nth orbit.
4. Derive the expression wave number.
5. Draw and explain the H2 spectrum and write the expression for each series.
6. Describe the production of X-rays in Coolidge tube.
7. The voltage applied across anode and cathode is 50 KV in an X-ray tube.  Calculate the energy of the electron striking the anode.                                                                          (50 Ke-v)
8. Calculate the wave length of the second member of the Lyman series of hydrogen  ( R=1.1 x 107 m-1   )                                                                                                                             (1023A0)
9. The energy of electron in the first orbit hydrogen atom is -13.6 e-v.   What will be its energy in the second orbit?
10.   Two energy levels are separated by 2.3 eV.   What is the frequency of radiation emitted when electron transited from upper to lower level.