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JEE Main20199 Jan 2019Morning ShiftPhysicsCurrent ElectricityActual

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

Options

  1. A0.2   Ω   m
  2. B4   Ω   m
  3. C2   Ω   m
  4. D0.4   Ω   m

Correct answer

D. 0.4   Ω   m

Step-by-step solution

Resistivity ρ = E J = E n e υ d = 1 n e μ μ = mobility ρ = 1 10 19 × 1.6 × 10 - 19 × 1.6 = 1 2.56   Ω   m = 0.4   Ω   m

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