Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NTA Abhyas JEE Main2020PhysicsDual Nature of MatterPractice

A light of intensity 16 m W and energy of each photon 10 e V incident on a metal plate of work function 5 eV and area 10 - 4 m 2 then find the maximum kinetic energy of emitted electrons and the number of photoelectrons emitted per second if photon efficiency is 10 %.

Options

  1. A5   eV ,   10 11
  2. B10   eV ,   10 12
  3. C5   eV ,   10 13
  4. D10   eV ,   10 14

Correct answer

A. 5   eV ,   10 11

Step-by-step solution

Maximum K E = h C λ - ϕ = 10 - 5 = 5   eV Intensity I = N p h C λ t A ⇒ N p t = I A h C λ and the number of emitted photoelectrons per second. = N p t × 10 % = I A h C λ × 1 10 = 16 × 10 - 3 × 10 - 4 10 × 1.6 × 10 - 19 × 10 = 10 11

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 NTA Abhyas JEE Main PYQs