Question

The length of a wire is 44cm and the radius is 0.7mm. If the resistance of the wire is 20 ohm, find the resistivity of the material (π=22/7)​

Answer 1

Answer:

ρ = 7 ₓ 10⁻⁷ Ωm

Explanation:

we know that

R = ρ L / A

ρ = RA / L

   = 20 × π (0.7 × 10⁻³)² / (44 ₓ 10⁻²)

  = (20 ₓ 22 ₓ 49 ₓ 10⁻⁸ ) / 7 ₓ (44 ₓ 10⁻²)

  = 21560 ₓ 10⁻⁸ / 308 ₓ 10⁻²

  = 70 ₓ 10⁻⁶

  =  7 ₓ 10⁻⁷ Ωm

..hope it helps..