Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main202127 Jul 2021Evening ShiftPhysicsDual Nature of MatterActual

An electron and proton are separated by a large distance. The electron starts approaching the proton with energy 3 eV . The proton captures the electrons and forms a hydrogen atom in second excited state. The resulting photon is incident on a photosensitive metal of threshold wavelength 4000 A What is the maximum kinetic energy of the emitted photoelectron?

Options

  1. A7 . 61   eV
  2. B1 . 41   eV
  3. C3 . 3   eV
  4. DNo photoelectron would be emitted

Correct answer

B. 1 . 41   eV

Step-by-step solution

Initially, energy of electron = + 3 eV finally, in 2 nd   excited state, energy of electron = - ( 13 . 6 eV ) 3 2 = - 1 . 51 eV Loss in energy is emitted as photon, So, photon energy hc λ = 4 . 51 eV Now, photoelectric effect equation KE max = hc λ - ϕ = 4 . 51 - hc λ th = 4 . 51 eV - 12400 eVA 4000 A = 1 . 41 eV

Practice Dual Nature of Matter on Quantrex Academy →

More from Dual Nature of Matter

K₁ and K₂ be the maximum kinetic energies of photoelectrons emitted from a surface of a given material for the light of wavelength ₁ and ₂ , respectively. If ₁=2 ₂ then the work fu 2026The de Broglie wavelength for an electron accelerated through the potential difference of V₁ volt is ₁ . When the potential difference is changed to V₂ volt, the associated de Brog 2026Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The electromagnetic wave exerts pressure on the surface on 2026An electron is travelling with a velocity v in free space and when it enters a medium, its velocity is reduced by 20 % . The de Broglie wavelength of electron in the medium is ₀ , 2026An electron of mass m is moving in an electric field E = -2E₀ i ( E₀ = constant > 0 ), with an initial velocity V = v₀ i ( v₀ = constant > 0 ). If ₀ = h 4mv₀ , its de Broglie wavel 2026Light source having wavelength 331 nm is used to generate photo-electrons whose stopping potential is 0.2 V. The work function of the used metal in the experiment is 10⁻¹⁹ J. The v 2026Match the List-I with List-II List-I List-II A. Planck's constant I. ML^2T⁻² B. Stopping potential II. T⁻¹ C. Work function III. ML^2T⁻¹ D. Threshold frequency IV. ML^2T⁻³A⁻¹ Choos 2026The de Broglie wavelength associated with an electron accelerated through a potential difference V is _e and the de Broglie wavelength associated with a proton accelerated through 2026 Full Dual Nature of Matter list All JEE Main PYQs