Main 30 · Advanced 23
Bohr model and hydrogen spectrum
- Advanced 2026PhysicsMultiple correct
Consider a hydrogen atom with , and denoting the velocity, orbital radius and kinetic energy of the electron in the orbit, respectively. The electron undergoes a transition from the orbit, emitting radiation corresponding to the Lyman series. Considering to be the Planck's constant and the permittivity of the free space, the correct statement(s) is/are:
- Main 2026PhysicsSingle correct
Angular momentum of an electron in a hydrogen atom is , then the energy of the electron is ________ eV.
- Main 2026PhysicsInteger
Using Bohr's model, calculate the ratio of the magnetic fields generated due to the motion of the electrons in the 2nd and 4th orbits of hydrogen atom ________.
- Main 2026PhysicsSingle correct
In the hydrogen atom, the electron makes a transition from the higher orbit () to a lower orbit (). The ratio of the radius of the orbits in given by . The wavelength of photon emitted due to this transition is ________ nm.
(Given Rydberg constant /m) - Main 2026PhysicsSingle correct
The ratio of momentum of the photons of the 1st and 2nd line of Balmer series of Hydrogen atoms is . The possible values of and are:-
- Advanced 2025PhysicsNumerical
Consider an electron in the orbit of a hydrogen-like atom with atomic number . At absolute temperature , a neutron having thermal energy has the same de Broglie wavelength as that of this electron. If this temperature is given by , (where is the Planck's constant, is the Boltzmann constant, is the mass of the neutron and is the first Bohr radius of hydrogen atom) then the value of is _____.
- Advanced 2025PhysicsList match
List-I shows various functional dependencies of energy () on the atomic number (). Energies associated with certain phenomena are given in List-II.
Choose the option that describes the correct match between the entries in List-I to those in List-II.
- Advanced 2025PhysicsNumerical
A hydrogen atom, initially at rest in its ground state, absorbs a photon of frequency and ejects the electron with a kinetic energy of 10 eV. The electron then combines with a positron at rest to form a positronium atom in its ground state and simultaneously emits a photon of frequency . The center of mass of the resulting positronium atom moves with a kinetic energy of 5 eV. It is given that positron has the same mass as that of electron and the positronium atom can be considered as a Bohr atom, in which the electron and the positron orbit around their center of mass. Considering no other energy loss during the whole process, the difference between the two photon energies (in eV) is _____.
- Advanced 2024PhysicsMultiple correct
A particle of mass is moving in a circular orbit under the influence of the central force , corresponding to the potential energy , where is a positive force constant and is the radial distance from the origin. According to the Bohr's quantization rule, the angular momentum of the particle is given by , where , is the Planck's constant, and a positive integer. If and are the speed and total energy of the particle, respectively, then which of the following expression(s) is(are) correct?
- Advanced 2023PhysicsInteger
A Hydrogen-like atom has atomic number . Photons emitted in the electronic transitions from level to level in these atoms are used to perform photoelectric effect experiment on a target metal. The maximum kinetic energy of the photoelectrons generated is 1.95 eV. If the photoelectric threshold wavelength for the target metal is 310 nm, the value of is _____.
[Given: eV-nm and eV, where is the Rydberg constant, is the Planck's constant and is the speed of light in vacuum]
- Main 2022PhysicsSingle correct
In Bohr's atomic model of hydrogen, let K, P and E are the kinetic energy, potential energy and total energy of the electron respectively. Choose the correct option when the electron undergoes transitions to a higher level :
- Main 2022PhysicsSingle correct
The ratio for the speed of the electron in the 3 orbit of to the speed of the electron in the 3 orbit of hydrogen atom will be :
- Main 2022PhysicsSingle correct
A hydrogen atom in its ground state absorbs 10.2 eV of energy. The angular momentum of electron of the hydrogen atom will increase by the value of :
(Given, Planck's constant Js).
- Main 2022PhysicsInteger
A beam of monochromatic light is used to excite the electron in from the first orbit to the third orbit. The wavelength of monochromatic light is found to be m. The value of is ______.
[Given eV nm]
- Main 2022PhysicsSingle correct
Given below are two statements:
Statement I: In hydrogen atom, the frequency of radiation emitted when an electron jumps from lower energy orbit () to higher energy orbit (), is given as
Statement II: The jumping of electron from higher energy orbit () to lower energy orbit () is associated with frequency of radiation given as
This condition is Bohr's frequency condition.
In the light of the above statements, choose the correct answer from the options given below:
- Main 2022PhysicsSingle correct
A hydrogen atom in ground state absorbs 12.09 eV of energy. The orbital angular momentum of the electron is increased by :
- Main 2022PhysicsInteger
A hydrogen atom in its first excited state absorbs a photon of energy eV and excited to a higher energy state where the potential energy of electron is eV. The value of is ______.
- Main 2022PhysicsSingle correct
The momentum of an electron revolving in n orbit is given by : (Symbols have their usual meanings)
- Main 2022PhysicsSingle correct
The magnetic moment of an electron (e) revolving in an orbit around nucleus with an orbital angular momentum is given by :
- Main 2022PhysicsSingle correct
Hydrogen atom from excited state comes to the ground state by emitting a photon of wavelength . The value of principal quantum number 'n' of the excited state will be : (R : Rydberg constant)