When the energy of incident radiation is increased by 20 % , the kinetic energy of the photoelectrons emitted from a metal surface increased from 0.5 eV to 0.8 eV . The work function of the metal is

Step-by-step solution

According to Einstein's photoelectric equation, E_K=E- ₀ where, E_K= kinetic energy, E= energy of incident photon and ₀= work function of metal surface. E=E_K+ ₀ (i) When energy of incident photon is increased by 20 % , then E^ =E+20 % of E=E+ 20 100 E= 6 E 5 E^ =1.2 E E_K^ =E^ - ₀ E^ =E_K^ + ₀1.2 E=E_K^ + ₀ (ii) From Eqs. (i) and (ii), we get E 1.2 E = E_K+ ₀ E_K^ + ₀ = 0.5+ ₀ 0.8+ ₀ [ E_K=0.5 eV . and E_K^ =0.8 eV ] 5 6 = 0.5+ ₀ 0.8+ ₀ 4+5 ₀=3+6 ₀ ₀=1 eV