AP EAMCET202125 Aug 2021Morning ShiftPhysicsDual Nature of MatterActual
When a light of wavelength 4900 Å falls on a photosensitive metal, a negative 2 ~V potential is required to stop the emitted electrons. Then, the work-function of the material is nearly ( given charge on electron =1.602 10⁻¹⁹ C and Planck's constant =6.625 10⁻³⁴ Js )
Options
- A1.1 eV
- B2.2 eV
- C0.53 eV
- D1 eV
Correct answer
C. 0.53 eV
Step-by-step solution
Given, wavelength of light, =4900 Å Stopping potential, V=2 ~V Energy of the incident light, aligned & E= 12400 eV Å & E= 12400 4900 eV =2.53 eV aligned Kinetic energy, KE = Stopping potential Charge of electron =2 e=2 eV Using Einstein's photoelectric equation, Kinetic energy = Energy of incident light - Work function aligned & 2=2.53- & =2.53-2=0.53 eV aligned