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Set 4 of 16 · Questions 91-120 of 453

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JEE Main Physics · Atoms · Set 4 (Q91-120)

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  1. 91.
    The energy (in ) required to excite an electron from to state in hydrogen atom
    1. (1)+2.55
    2. (2)-3.4
    3. (3)+4.25
    4. (4)-0.85
  2. 92.
    If an electron is moving in the orbit of the hydrogen atom then the angular momentum of the electron in SI units is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  3. 93.
    A radio active material is reduced to of its original amount in 3 days. If 8 x 10-3 kg of the material is left after 5 days the initial amount of the material is
    1. (1)40 g
    2. (2)32 g
    3. (3)64 g
    4. (4)256 g
  4. 94.
    The radiation corresponding to transition of hydrogen atom falls on a metal surface to produce photoelectrons. These electrons are made to enter a magnetic field of . If the radius of the largest circular path followed by these electrons is 10.0 mm , the work function of the metal is close to :
    1. (1)1.8 eV
    2. (2)1.1 eV
    3. (3)0.8 eV
    4. (4)1.6 eV
  5. 95.
    Choose the correct nuclear process from the below options [ p : proton, neutron, : electron, positron, : neutrino, : antineutrino]
    1. (1)
    2. (2)p→n+e++v
    3. (3)p→n+e-+v
    4. (4)
  6. 96.
    If the first line of Lyman series has a wavelength , the first line of Balmer series is approximately
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  7. 97.
    If the radius of the first Bohr orbit is ' ' then the de-Broglie wavelength of the electron in the orbit will be
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  8. 98.
    When an electron does transition from to , then emitted line spectrum will be
    1. (1)first line of Lyman series
    2. (2)second line of Balmer series
    3. (3)first line of Paschen series
    4. (4)second line of Paschen series
  9. 99.
    A hydrogen atom at the ground level absorbs a photon and is excited to level. The potential energy of the electron in the excited state is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  10. 100.
    The half life period of a radioactive substance is 60 days. The time taken for th of its original mass to disintegrate will be:
    1. (1)120 days
    2. (2)130 days
    3. (3)180 days
    4. (4)20 days
  11. 101.
    The ground state energy of ‐atom is 13.6 The energy needed to ionize ‐atom from its second excited state
    1. (1)1.51 eV
    2. (2)3.4 eV
    3. (3)13.6 eV
    4. (4)none of these
  12. 102.
    The disintegration rate of a certain radioactive sample at any instant is 4250 disintegrations per minute. 10 minutes later, the rate becomes 2250 disintegrations per minute. The approximate decay constant is: (Take l.88 = 0.274)
    1. (1)0.02
    2. (2)2.7
    3. (3)0.063
    4. (4)6.3
  13. 103.
    A photon released by the transition of an electron from the second excited state to the ground state of Hydrogen atom is incident on the surface of a metal of work function . The de Broglie wavelength of the most energetic electron emitted from that metal surface is nearly
    1. (1)
    2. (2)
    3. (3)
    4. (4)None
  14. 104.
    A particle is moving 5 times as fast as an electron. The ratio of the de-Broglie wavelength of the particle to that of the electron is . The mass of the particle is close to:
    1. (1) kg
    2. (2) kg
    3. (3) kg
    4. (4) kg
  15. 105.
    In ruby laser, the stimulated emission is due to transition from
    1. (1)metastable state to any lower state
    2. (2)any higher state to lower state
    3. (3)metastable state to ground state
    4. (4)any higher state to ground state.
  16. 106.
    The de-Broglie wavelength of the electron in the ground state of the hydrogen atom is (radius of the first orbit of hydrogen atom ).
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  17. 107.
    The ratio of the magnetic dipole moment to the angular momentum of the electron in the orbit of hydrogen atom is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  18. 108.
    Energy of a stationary electron in the hydrogen atom is then the energies required to excite the electron in hydrogen atom to (i) its second excited state and (ii) ionized state respectively
    1. (1)(i) , (ii) 13.6eV
    2. (2)(i) , (ii)
    3. (3)(i) ∼12eV, (ii)
    4. (4)(i) , (ii) 13.6eV
  19. 109.
    In a nuclear fission reaction of an isotope of mass , three similar daughter nuclei of same mass are formed. The speed of a daughter nuclei in terms of mass defect will be :
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  20. 110.
    Which level of the single ionized carbon has the same energy as the ground state energy of hydrogen atom?
    1. (1)1
    2. (2)6
    3. (3)4
    4. (4)8
  21. 111.
    The ratio of longest wavelengths of the spectral lines in the Lyman and Balmer series of hydrogen spectrum is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  22. 112.
    Choose the correct option from the following options given below:
    1. (1)In the ground state of Rutherford's model electrons are in stable equilibrium. While in Thomson's model electrons always experience a net-force.
    2. (2)An atom has a nearly continuous mass distribution in a Rutherford's model but has a highly non-uniform mass distribution in Thomson's model
    3. (3)A classical atom based on Rutherford's model is doomed to collapse.
    4. (4)The positively charged part of the atom possesses most of the mass in Rutherford's model but not in Thomson's model.
  23. 113.
    The collision of an electron with kinetic energy and a hydrogen atom in its ground state can be described as
    1. (1)completely inelastic
    2. (2)may be completely inelastic
    3. (3)may be partially elastic
    4. (4)elastic
  24. 114.
    The period of revolution of an electron revolving in orbit of -atom is proportional to
    1. (1)
    2. (2)independent of
    3. (3)
    4. (4)
  25. 115.
    The radius of third stationary orbit of electron for Bohr's atom is . The radius of fourth stationary orbit will be:
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  26. 116.
    Angular momentum of an electron in hydrogen atom is ( is the Planck's constant). The K.E. of the electron is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  27. 117.
    The mass defect in a particular reaction is . The amount of energy liberated is , where (speed of light )
  28. 118.
    A freshly prepared radioactive source of half life 2 hours 30 minutes emits radiation which is 64 times the permissible safe level. The minimum time, after which it would be possible to work safely with source, will be________hours.
  29. 119.
    If the binding energy of ground state electron in a hydrogen atom is 13.6 eV, then, the energy required to remove the electron from the second excited state of will be: x x eV. The value ofxis
  30. 120.
    Radius of a certain orbit of hydrogen atom is . If energy of electron in this orbit is . then (Given energy of electron in ground state).