Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE MainPhysicsDual Nature of Matter

The work functions of metal A and metal B are 2.0 eV and 3.1 eV , respectively. When monochromatic light of wavelength is incident on both the metals, photoelectric emission is observed from metal A but not from metal B. Which of the following could be the value of ? (Take hc = 1240 eV nm )

Options

  1. A310 nm
  2. B650 nm
  3. C550 nm
  4. D380 nm

Correct answer

C. 550 nm

Step-by-step solution

For photoelectric emission to occur, the energy of the incident photon must be greater than the work function of the metal ( E > ). Given that emission occurs for metal A but not for metal B, the incident photon energy E must satisfy: _A 2.0 eV The energy of a photon is given by E = hc = 1240 eV , where is in nm. Checking the given options: For = 310 nm , E = 1240 310 = 4.0 eV (Emission from both) For = 650 nm , E = 1240 650 1.91 eV (Emission from neither) For = 550 nm , E = 1240 550 2.25 eV (Emission from A only)

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