AP EAMCET202125 Aug 2021Morning ShiftChemistryStructure of AtomActual
If the maximum kinetic energy of photoelectrons ejected from a metal surface when it is irradiated with a radiation of frequency 4 10¹⁴ ~s ⁻¹ is 6.63 10⁻²⁰ ~J , then the threshold frequency of the metal is
Options
- A2 10¹⁴ ~s ⁻¹
- B1 10¹⁴ ~s ⁻¹
- C3 10¹⁴ ~s ⁻¹
- D1 10⁻¹⁴ ~s ⁻¹
Correct answer
C. 3 10¹⁴ ~s ⁻¹
Step-by-step solution
The threshold energy for production of a particle is the minimum K.E., a pair of travelling particles must have when they collide. aligned Absorbed energy & = KE + threshold energy h v^ & = KE +h v₀^ h v₀^ & =h v^ - KE aligned aligned & 6.26 10⁻³⁴ v₀ & =6.26 10⁻³⁴ 4 10¹⁴-6.63 10⁻²⁰ ~J & v₀=2.999 10¹³ ~s ⁻¹=3 10¹⁴ ~s ⁻¹ & aligned Hence, threshold frequency (v₀^ ) of metal is 3 10¹⁴ ~s ⁻¹