The electrical conductivity of a semiconductor increases when electromagnetic radiation of wavelength shorter than `2480 nm` is incident on it. The band gap in `(eV)` for the semiconductor is.

Options

A. 0.9
B. 0.7
C. 0.5
D. 1.1

Answer

C

Explanation

Band gap, `E=(hc)/(lamda)`
`=(66x10^(-34)xx3xx10^(8))/(2480xx10^(-9))`
`=(198xx10^(-17))/(2480)=8xx10^(-20)J`
`=(8xx10^(-20))/(16xx10^(-19))eV`
`=5xx10^(-1)=0.5`eV