Question

The lowest frequency of light that will cause the emission of photoelectrons from the surface of a metal (for which work function is 1.65 eV) will be

• A. $4\times {10}^{10}Hz$
• B. $4\times {10}^{11}Hz$
• C. $4\times {10}^{14}Hz$
• D. $4\times {10}^{-10}Hz$

Answer 1

The correct option is C

$4\times {10}^{14}Hz$

Minimum frequency : $W_0=h{v}_0$
$\Rightarrow v_0=\frac{W_0}{h}=\frac{1.65\times 1.6\times {10}^{-19}}{6.6\times {10}^{-34}}=4\times {10}^{14}Hz$