The work function of a substance is 3 . 0 eV . The longest wavelength of light that can cause the emission…

The work function of a substance is 3.0 eV. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately:
  1. 215 nm
  2. 414 nm
  3. 400 nm
  4. 200 nm

Solution

For longest wavelength, the emitted electron will have nearly zero kinetic energy.

Therefore,

λ=hcWe

⇒λ=1240 nm-eV3 eV

⇒λ=413.33 nm

⇒λmax≈414 nm

Asked in: JEE Main 2024 (30 Jan Shift 1)

Practice more Dual Nature of Matter and Radiation questions on Aicharya