For ionization of excited Hydrogen atom, the, required energy is:
  • a little less than 13.6
  • equal to 13.6
  • more than 13.6
  • 3.4 or less
An atom stays in an excited state for about:
  • 10 micro seconds
  • 10 milli seconds
  • 10 nano seconds
  • 10 seconds
The energy equivalent to one atomic mass unit is :
  • 1.6 × 10-19 J
  • 6.02 × 1023 J
  • 9.31 MeV
  • 931 MeV
Who explained the splitting of special lines in magnetic field?
  • Zeeman
  • Bohr
  • Summerfield
  • Einstein
The mass of a neutron is:
  • 1.00866 u
  • 1.0866 u
  • 1.866 u
  • 0.1866 u
Isobars have the same:
  • A
  • Z
  • N
  • All the above
Isotones have the same:
  • A
  • Z
  • N
  • All the above
Half-life of a substance depends on:
  • pressure
  • temperature
  • density
  • None of these
The concept of electron spin was introduced by:
  • Becquerel
  • Goudsmit
  • Millikan
  • Uhlenbeek and Goudsmit
The principle that a quantum orbital cannot be occupied by more than two electrons was given by:
  • Pauli
  • Millikan
  • Hund
  • None of these
According to Bohr's theory of hydrogen atom, the radius r of stationary orbit are related to principal quantum number n as:
  • rg ∝ \(\frac{1}{n^2}\)
  • rg ∝ \(\frac{1}{n}\)
  • rg ∝ n
  • rg ∝ n²
Fg and Fe represents the gravitational and electrostatic force respectively between two electrons situated at some distance the ratio \(\frac{F_g}{F_e}\) is if the order of:
  • 9.8
  • 109
  • 1042
  • 10-42
Artificial radioactivity was discovered by:
  • Joliot
  • Becquerel
  • Pauli
  • None of these
P-decay produces:
  • isobars
  • isotopes
  • isotones
  • All the above
Natural radioactivity was discovered by:
  • Joliot
  • Becquerel
  • Pauli
  • None of these
Transmutation of nuclei was discovered by:
  • Rutherford
  • Becquerel
  • Pauli
  • None of these
The energy equivalent to mass defect is called :
  • binding energy
  • internal energy
  • external energy
  • enthalpy
The total energy that will be released if a nucleus is built from its constituents is called the:
  • binding energy of the nucleus
  • binding energy of the solid
  • binding energy of the atom
  • None of these
The binding energy of \(_{2}^{4}\)He is about:
  • 28.3 eV
  • 28.3 MeV
  • 28.3 J
  • 2.83 MeV
The binding energy of a deuteron is about:
  • 2.22 MeV
  • 2.22 J
  • 2.22 eV
  • None of these
0 h : 0 m : 1 s

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