Question

If work function of a photoelectric material is $3.3eV$, then threshold frequency will be:

• A. $8\times {10}^{14}Hz$
• B. $8\times {10}^{56}Hz$
• C. $8\times {10}^{10}Hz$
• D. $8\times {10}^{4}Hz$

Answer 1

Answer: (A)

$8\times {10}^{14}Hz$

$W_0=h{v}_0$

$\Rightarrow v_0=\frac{W_0}{h}$

$=\frac{3.3\times 1.6\times {10}^{-19}}{6.6\times {10}^{-34}}$

$=\frac{528}{660}\times {10}^{15}$

$=8\times {10}^{14}Hz$