Question

The work fuction of a photo electric material is $3.3eV$. Its threshold frequency will be:

• A. $4\times {10}^{23}Hz$
• B. $8\times {10}^{12}Hz$
• C. $4\times {10}^{11}Hz$
• D. $8\times {10}^{14}Hz$

Answer 1

Answer: (D)

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

Work function = planck constant × threshold frequency

${\varphi }_0=h\times {\nu }_0$

$3.3\times 1.6\times {10}^{-19}=6.625\times {10}^{-34}\times {\nu }_0$

${\nu }_0=8\times {10}^{14}$Hz