Question

Light of wavelength 5000 $A^0$ is incident on a metallic surface of work function 3.31 eV. Then photoelectric emission is

• A. Possible
• B. Not possible
• C. May or may not be possible
• D. Data insufficient

Answer 1

The correct option is B Not possible

Energy of photon $=\frac{hc}{\lambda }$
$=\frac{20\times {10}^{-26}}{5000\times {10}^{-19}}$
$=4\times {10}^{-19}J$

$=2.5eV$

$\because$ Energy of photon < work function

So, emission is not possible. So, the answer is option (B).