Q120 / 125 · BITSAT 2010 · Physics

The photoelectric threshold of metal is $2000 \AA$. The energy of the electrons ejected from the surface by ultraviolet light of wavelength $1500 \AA$ is

  • Correct answer
    A
    $2.0 \mathrm{eV}$
  • B
    $1.5 \mathrm{eV}$
  • C
    $15 \mathrm{eV}$
  • D
    $150 \mathrm{eV}$

Solution

$\mathrm{E}_{\mathrm{k}}=\frac{\mathrm{hc}}{\mathrm{e}}\left(\frac{1}{\lambda}-\frac{1}{\lambda_{0}}\right)=2.0 \mathrm{eV}$

Hence, the correct answer is option: 'A'.

Relevant Questions