Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 202621 JanuaryEvening Shift
Exam
JEE Main
Year
2026
Date
21 January
Shift
Evening Shift
Subject
Physics
Chapter
Atomic Physics

JEE Main 2026 · 21 January · Evening Shift · Physics · Atomic Physics

The energy of an electron in an orbit of the Bohr's atom is -0.04...

The energy of an electron in an orbit of the Bohr's atom is −0.04E0eV-0.04 E_{0} \mathrm{eV} where E0E_{0} is the ground state energy. If LL is the angular momentum of the electron in this orbit and hh is the Planck's constant, then 2πLh\frac{2 \pi L}{h} is ____\_\_\_\_ :

Options

  1. A5
  2. B6
  3. C2
  4. D4

Correct answer

A. 5

Step-by-step solution

In Bohr's atom, the energy levels are En=−E0n2E_n = -\frac{E_0}{n^2} where E0E_0 is the ground state energy.
Given E=−0.04E0E = -0.04E_0, we have −E0n2=−0.04E0-\frac{E_0}{n^2} = -0.04E_0, which gives n2=25n^2 = 25, so n=5n = 5.
The angular momentum in Bohr's model is L=nℏ=nh2πL = n\hbar = n\frac{h}{2\pi}.
Therefore, 2πLh=2πh×nh2π=n=5\frac{2\pi L}{h} = \frac{2\pi}{h} \times n\frac{h}{2\pi} = n = 5.
Practice Atomic Physics on Quantrex Academy →

More from Atomic Physics

Consider a hydrogen atom with v_k , r_k , and K_k denoting the velocity, orbital radius… JEE Advanced 2026The ratio of momentum of the photons of the 1^ st and 2^ nd line of Balmer series of… JEE Main 2026In the hydrogen atom, the electron makes a transition from the higher orbit ( i ) to a… JEE Main 2026In Rutherford's alpha-particle scattering experiment, only a few alpha particles rebound… JEE Main 2026Using Bohr's model, calculate the ratio of the magnetic fields generated due to the… JEE Main 2026Angular momentum of an electron in a hydrogen atom is (3h)/(π) , then the energy of the… JEE Main 2026Two electrons are moving in orbits of two hydrogen like atoms with speeds 3 × 10^ 5 ~m /… JEE Main 2026In hydrogen atom spectrum, (R arrow Rydberg's constant ) A. the maximum wavelength of the… JEE Main 2026 Full Atomic Physics list All JEE Main PYQs