Question

The forbidden energy gap in $Ge$ is $0.72\, eV$. Given, $hc = 12400 \, eV \, - ?$ . The maximum wavelength of radiation that will generate an electron hole pair is

• A. $17222\, ?$
• B. $1722\, ?$
• C. $172220\, ?$
• D. $172.2\, ?$

Answer 1

Answer: (A)

$17222\, ?$

Answer 2

Energy gap, $E_{g}=\frac{h c}{\lambda}$ $\lambda=\frac{h c}{E_{g}}=\frac{12400}{0.72}=17222\, ?$