Question

If the work function for a certain metal is $3.2\times {10}^{-19}joule$ and it is illuminated with light of frequency $8\times {10}^{14}Hz$. The maximum kinetic energy of the photo-electrons would be $(h=6.63\times {10}^{-34}Js$

• A. $2.1\times {10}^{-19}J$
  
• B. $8.5\times {10}^{-19}J$
  
• C. $5.3\times {10}^{-19}J$
  
• D. $3.2\times {10}^{-19}J$
  

Answer 1

The correct option is A $2.1\times {10}^{-19}J$


$K_{max}=hv-W_0=6.6\times {10}^{-34}\times 8\times {10}^{14}-3.2\times {10}^{-19}$
$=2.1\times {10}^{-19}J$