Q. If the work function for a certain metal is $3.2 \times 10^{- 19}J$ and it is illuminated with light of frequency $v = 8 \times 10^{14}$Hz, the maximum kinetic energy of the photoelectron would be
A) $2.1 \times 10^{- 19}J$
B) $3.2 \times 10^{- 19}J$
C) $5.3 \times 10^{- 19}J$
D) $8.5 \times 10^{- 19}J$
Explanation
(a) Maximum KE $= hv - \phi_{0}$
$= 6.63 \times 10^{- 34} \times 8 \times 10^{14} - 3.2 \times 10^{- 19}$
$= 2.1 \times 10^{- 19}J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.