Verified Solution • 2025–26 Session moderate

QJEEM19Phd5f9: JEE Main 2019 Physics - Class 12 JEEM19Phd5f9 Solution: In a conductor, if the number of conduction electrons per unit…

In a conductor, if the number of conduction electrons per unit volume is 8.5 × 1028 m–3 and mean free time is 25ƒs (femto second), it's approximate resistivity is :-
(me = 9.1 × 10–31 kg)

Multiple Choice Options

  • A 10–8 Ω\Omega m
  • B 10–7 Ω\Omega m
  • C 10–5 Ω\Omega m
  • D 10–6 Ω\Omega m

Step-by-Step Verified Solution

ρ=2mne2τ\rho = {{2m} \over {n{e^2}\tau }}

= 3.34 × 10–8 Ω\Omega m

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