Question

The work function of a metal is $5 \,eV$. What is the kinetic energy of the photoelectron ejected from the metal surface if the energy of the incident radiation is $6.2\, eV$ ?
($1 eV = 1.6 \times 10^{-19} J$)

• A. $6.626 \times 10^{-19} J$
• B. $8.01 \times 10^{-19} J$
• C. $1.92 \times 10^{-18} J$
• D. $8.010 \times 10^{-18} J$
• E. $1.92 \times 10^{-19} J$

Answer 1

Answer: (E)

Work function $(W)=h v_{0}=5\, eV$

Energy of incident radiation,

$h v=6.2 \,eV$

Kinetic energy of photoelectron

$=h v-W$

$=6.2-5 $

$=1.2 \,eV $

$=1.2 \times 1.6 \times 10^{-19}\, J$

$=1.92 \times 10^{-19}\, J$