• question_answer The width of depletion region in p-n junction diode is 500 nm and an internal electric field of $6\times {{10}^{5}}\,V{{m}^{-1}}$is also found to exist in it. What is the kinetic energy which a conduction electron must have in order to diffuse from the $n-$side to $p-$side? A)  0.03 eV                       B)  0.30 eV           C)    0.45 eV           D)    0.60 eV

Here, $E=6\times {{10}^{5}}\,V{{m}^{-1}};\,d=500\times {{10}^{-9}}\,m$ Here, height of potential barrier, ${{V}_{B}}=Ed=6\times {{10}^{5}}\times 500\times {{10}^{-9}}=0.30\,V$ Maximum K.E. of and electron to cross the potential barrier $=e{{V}_{B}}=e\times (0.30\,V)=0.30\,eV.$ Hence, the correction option is (b).