Question

If the work function of a metal is $0.8275\text{eV}$. Its threshold frequency falls in the region of

• A. Ultraviolet Region
• B. Infrared Region
• C. Radio Region
• D. Microwave Region.

Answer 1

The correct option is B Infrared Region

The formula for work function is given by,

$\varphi =h{\nu }_0$

${\nu }_0=\frac{\varphi }{h}=\frac{0.8275\times 1.6\times {10}^{-19}}{6.63\times {10}^{-34}}=2\times {10}^{14}\text{Hz}$

The frequency range of Infrared region is given by,

${10}^{13}\text{Hz}-4\times {10}^{14}\text{Hz}\to I-RRegion$

Hence, option $\left(B\right)$ is correct.