The value of work function of a metal $\mathrm{X}$ is $3.1 \mathrm{eV}$. The threshold frequency of it (in…
The value of work function of a metal $\mathrm{X}$ is $3.1 \mathrm{eV}$. The threshold frequency of it (in $\mathrm{Hz})\left(\mathrm{h}=6.62 \times 10^{-34} \mathrm{Js}\right)$
$6.49 \times 10^{13}$
$5.49 \times 10^{13}$
$6.49 \times 10^{14}$
$7.49 \times 10^{14}$
Solution
Work function $(\phi)=3.1 \mathrm{eV}=3.1 \times 1.6 \times 10^{-19} \mathrm{~J}$
Threshold frequency $\left(v_0\right)=\frac{E}{h}=\frac{3.1 \times 1.6 \times 10^{-19}}{6.626 \times 10^{-34}} \mathrm{~s}^{-1}$
$
=0.748 \times 10^{15} \mathrm{~s}^{-1}=7.48 \times 10^{14} \mathrm{~Hz}
$