List of top Physics Questions on Atomic Physics asked in JEE Main

The smallest wavelength of Lyman series is \(91\ \text{nm}\). The difference between the largest wavelengths of Paschen and Balmer series is nearly _________ nm.
As shown in the diagram, when the incident ray is parallel to base of the prism, the emergent ray grazes along the second surface. If refractive index of the material of prism is $\sqrt{2}$, the angle $\theta$ of prism is :
Bohr’s radius of H-atom is \( 2.12 \times 10^{-10} \) m. Calculate the energy of electron at this level.
Among the given options choose the correct energy of transition:
Energy of first line of Lyman series - A Energy of second line of Balmer series - B Energy of first line of Balmer series - C Energy of second line of Lyman series - D What will be the correct decreasing order of energies of photons?
Given below are two statements:
Statement I: When electric discharge is put on hydrogen, it emits discrete frequency in the electromagnetic spectrum.
Statement II: Frequency of He\(^+\) ion of 2\(^\text{nd}\) line of Balmer series is equal to first line of Lyman series.
In the light of the above statements, choose the correct option.
Line corresponding to lyman series are $\text{L}_1, \text{L}_2, \text{L}_3, \text{L}_4, \ldots$, among these $\text{L}_1$ line corresponds to lowest energy. Similarly lines corresponding to balmer series are $\text{B}_1, \text{B}_2, \text{B}_3, \text{B}_4, \ldots$, among these $\text{B}_1$ line corresponds to lowest energy $\Delta E_L = \text{Energy of } 1^{\text{st}} \text{ line of lyman series}$, $\Delta E_B = \text{Energy of } 1^{\text{st}} \text{ line of balmer series}$. If $\Delta E_L = x \cdot \Delta E_B$. Calculate $(x \times 10^{-1})$
In a H-like ion, ratio of speed of electron in two orbit is 3 : 2, then ratio of energies in these orbits should be :
The energy required to excite an electron from the first Bohr orbit of a hydrogen atom to the second Bohr orbit is:
A photon is incident on a particle having mass \(m = 15.356\,\text{amu}\). What should be the frequency of the photon so that the particle of mass \(m\) breaks into four \(\alpha\)-particles? (Given: \(m_\alpha = 4.004\,\text{amu}\); \(h = 6.6\times10^{-34}\,\text{J s}\))
Match the following:
Choose the correct option:
An \(\alpha\)-particle is projected towards a fixed gold nucleus (\(Z=79\)) with kinetic energy \(7.9\,\text{MeV}\). If the particle is just able to touch the nuclear boundary, find the diameter of the nucleus.
An electron in the ground state of the hydrogen atom has the orbital radius of \( 5.3 \times 10^{-11} \, \text{m} \) while that for the electron in the third excited state is \( 8.48 \times 10^{-10} \, \text{m} \). The ratio of the de Broglie wavelengths of the electron in the ground state to that in the excited state is:
Assuming the validity of Bohr's atomic model for hydrogen-like ions, the radius of $ \text{Li}^{2+} $ ion in its ground state is given by $ \frac{1}{X} a_0 $, where $ a_0 $ is the first Bohr's radius.

An electron in the hydrogen atom initially in the fourth excited state makes a transition to \( n^{th} \) energy state by emitting a photon of energy 2.86 eV. The integer value of n will be 1cm.

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : The Bohr model is applicable to hydrogen and hydrogen-like atoms only. Reason R : The formulation of Bohr model does not include repulsive force between electrons. In the light of the above statements, choose the correct answer from the options given below :

Considering the Bohr model of hydrogen like atoms, the ratio of the radius $5^{\text {th }}$ orbit of the electron in $\mathrm{Li}^{2+}$ and $\mathrm{He}^{+}$is

A particular hydrogen-like ion emits the radiation of frequency $3 \times 10^{15}$ Hz when it makes a transition from $n = 2$ to $n = 1$. The frequency of radiation emitted in the transition from $n = 3$ to $n = 1$ is \[\frac{x}{9} \times 10^{15} \, \text{Hz}, \, \text{when} \, x = _____ .]
The shortest wavelength of the spectral lines in the Lyman series of hydrogen spectrum is 915 Å. The longest wavelength of spectral lines in the Balmer series will be _______ Å.
The angular momentum of an electron in a hydrogen atom is proportional to: (Where \( r \) is the radius of the orbit of the electron)
A hydrogen atom changes its state from \( n = 3 \) to \( n = 2 \). Due to recoil, the percentage change in the wavelength of emitted light is approximately \( 1 \times 10^{-n} \). The value of \( n \) is ______. \([ \text{Given: } Rhc = 13.6 \, \text{eV}, \, hc = 1242 \, \text{eV nm}, \, h = 6.6 \times 10^{-34} \, \text{J s}, \, \text{mass of the hydrogen atom} = 1.6 \times 10^{-27} \, \text{kg} ]\)
The minimum energy required by a hydrogen atom in ground state to emit radiation in Balmer series is nearly :
When a hydrogen atom going from \( n = 2 \) to \( n = 1 \) emits a photon, its recoil speed is \( \frac{x}{5} \) m/s. Where \( x = \, \) _____. (Use: mass of hydrogen atom \( = 1.6 \times 10^{-27} \, \text{kg} \))
The metallic bob of simple pendulum has the relative density 5. The time period of this pendulum is 10 s. If the metallic bob is immersed in water, then the new time period becomes 5√x s. The value of x will be _____.
Two radioactive materials A and B have decay constants 25λ and 16λ respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of B to that of A will be ‘e’ after a time \(\frac{1}{(aλ)}\). The value of a is _____.