Question

The thickness of the depletion region is of the order of ___________ of a micrometre.

• A. one-hundredth
• B. one-tenth
• C. one-thousandth
• D. None of these

Answer 1

Answer: (D)

Depletion region is a region near the p-n junction where flow of charge carriers (free electrons and holes) is reduced over a given period and finally results in zero charge carriers.The width of depletion region which is generally $1\mu m$, depends on the amount of impurities added to the semiconductor. Impurities are the atoms (pentavalent and trivalent atoms) added to the semiconductor to improve its conductivity.

hence answer is $1\mu m$ and correct option is $D$ - none of these.