i.e. the incident frequency is less than threshold frequency. Hence there will be no emission of photoelectrons.
\(\Rightarrow\) current \(=0\)
$(\left| e \right| = 1.6 \times {10^{ - 19}}\,\,C,\,\,{m_e} = 9.1 \times {10^{ - 31}}\,kg,\,\,h = 6.6 \times {10^{ - 34}}\,\,Js)$