Given the value of rydberg constant is 10 m^{-1}, the wave number of the last line of the Balmer series in hydrogen spectrum will be:
0.5 x 10^{7} m^{-1}
0.25 x 10^{7} m^{-1}
2.5 x10^{7 }m^{-1}
2.5 x10^{7 }m^{-1}
The ratio of escape velocity at earth (V_{e}) to the escape velocity at a planet (v_{p}) whose radius and mean density are twice as that of earth is,
1:
1:4
1:
1:
Consider 3^{rd} orbit of He^{+} (Helium)_{,} using non-relativistic approach, the speed of electron in this orbit will be (given K= 9 x 10^{9} constant, Z=2 and h (Planck's constant = 6.6 x 10^{-34} Js^{-1}
2.92 x 10^{6} m/s
1.46 x 10^{6} m/s
0.73 x 10^{6} m/s
0.73 x 10^{6} m/s
A proton carrying 1 MeV kinetic energy is moving in a circular path of radius R in the uniform magnetic field. What should be the energy of an alpha particle to describe a circle of the same radius in the same field.
2 MeV
1 MeV
0.5 MeV
0.5 MeV
The transition from the state n = 3 to n=1 in a hydrogen-like atom results in ultraviolet radiation. Infrared radiation will be obtained in the transition from.
2→ 1
3 →2
4 → 2
4 → 2
D.
4 → 2
Infrared radiation is found in Paschen, Brackett and pfund series nd it is obtained when electron transition occurs from high energy level to minimum third level.
An electron in hydrogen atom first jumps from third excited state to second excited state and then from second excited to the first excited state. The ratio of the wavelengths λ_{1}:λ_{2} emitted in the two cases is
7/5
27/20
27/5
27/5
An electron of a stationary hydrogen atom passes from the fifth energy level to ground level. The velocity that the atom acquired as a result of photon emission will be
Hydrogen atom in ground state is excited by a monochromatic radiation of . The number of spectral lines in the resulting spectrum emitted will be,
3
2
6
6
The wavelength λ_{e} of an electron and λ_{p} of a photon of same energy E are related by
A certain mass of hydrogen is changed to helium the process of fusion. The mass defect in fusion reaction is 0.02866 u. The energy liberated per u is (given 1 u =931 MeV)
2.67 MeV
26.7 MeV
6.675 MeV
6.675 MeV