Question

A wire of length 40 cm and area of cross -section 0.1 mm² has a resistance of 0.8Ω. Calculate specific resistance of the wire.​

Answer 1

$l = 40cm \\ \bold \red{area \: of \: cross \: section} \: a = 0.1mm {}^{2} \\ = \frac{0.1}{100} cm {}^{2} \\ \\ \R = 0.8 Ω \\ \\ \bold \green{ Specific \: Resistance \: of \: wire \:ρ } = \frac{Ra}{l} \\ = \frac{0.8}{40} \times \frac{1}{100} \\ \\ ρ = 0.00002Ω - cm$

Hope This Helps!!

Answer 2

The specific resistance of the wire is 2.0 × 10⁻⁷ Ωm

Calculating specific resistance

From the question, we are to determine the specific resistance of the wire

From the formula,

$\rho = \frac{RA}{l}$

Where $\rho$ is the specific resistance or resistivity

R is the resistance

A is the cross section area

and $l$ is the length of the wire

From the given information

$l = 40\ cm = 0.4 \ m$

$A = 0.1 \ mm^{2} = 0.1 \times 10^{-6} \ m^{2}$

R = 0.8 Ω

Putting the parameters into the formula, we get

$\rho = \frac{0.8 \times 0.1 \times 10^{-6} }{0.4}$

Then,

$\rho = 2.0 \times 10^{-7}$ Ωm

Hence, the specific resistance of the wire is 2.0 × 10⁻⁷ Ωm

Learn more on Calculating specific resistance here: https://brainly.com/question/4170002