What is the conductivity of a wire of resistance $0.05 \Omega$, area of cross section $2 \times 10^{-4} m^2$ and length 50 cm?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → $5 \times 10^4 \Omega^{-1} m^{-1}$
Given,
$ρ=R\frac{A}{L}$ [formula]
where,
$ρ$ = Resistivity
$A = 2×10^{-4}m^2$ [given]
$L=50cm=0.5m$
$σ=\frac{1}{ρ}=\frac{0.5}{2×10^{-4}×0.05}$
$=\frac{1}{2}×10^{-5}$
$=5×10^{4}s/m$