Current Electricity

JEE Main level, single correct, medium

33 of 380

Question 33 of 380

Mobility of electrons in a semiconductor is defined as the ratio of their drift velocity to the applied electric field. If, for an N\text{N}-type semiconductor, the density of electrons is 1019m−3{10}^{19}{m}^{-3} and their mobility is 1.6m2V−1s−11.6{m}^{2}{V}^{-1}{s}^{-1}, then the resistivity of the semiconductor (since it is an N\text{N}-type semiconductor contribution of holes is ignored) is close to:

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Answer: (D) 0.4Ωm0.4\Omega m

Resistivity ρ=EJ=Eneυd=1neμ\rho =\dfrac{E}{J}=\dfrac{E}{ne{υ}_{d}}=\dfrac{1}{ne\mu }

μ=\mu = mobility

ρ=11019×1.6×10−19×1.6=12.56Ωm\rho =\dfrac{1}{{10}^{19}\times 1.6\times {10}^{-19}\times 1.6}=\dfrac{1}{2.56}\Omega m

=0.4Ωm=0.4\Omega m

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