The electrical conductivity of a semiconductor increases when electromagnatic radiation of wavelength shorter than 2480 nm is incident on it. Find the band gap of the semiconductor. Given `h=6.63xx10^(-34)Js, and 1eV=1.6xx10^(-19)J`.

Explanation

Band gap, `E_(g)=hv=(hc)/l(ambda)`
`=((6.63xx10^(-34))xx(3xx10^(8)))/(2480xx10^(-9))=8.02xx10^(-20)J`
`=(8.02xx10^(20))/(1.6xx10^(-19))~~0.5eV`