For germenium crystal, the forbidden energy gap in joules is

Options

A. zero
B. `1.6xx10^(-19)`
C. `1.1xx10^(-19)`
D. `1.76xx10^(-19)`

Answer

C

Explanation

Semiconductors are similar to ionsulators but the conduction and valence bands are spaced closely, so that at room temperature, a number of electrons are found in conduction band. For germanium, forbidden energy gap
`=0.67eV=0.67xx1.6xx10^(-19)=1.1xx10^(-19)J`