Question

Calculate the resistance of a 2 m long wire of radius 2 m m . The resisitivity of metal of wire is 5*10-8 m

Answer 1

Explanation:

Given

l=2 m

r=2×10^-3m

A=3.14×4×10^-6

12.56×10^-6m^2

p=5×10^-8

R=pl/A

=5×10^-8×2/12.56×10^-6

8×10^-3ohms

Answer 2

Answer:

The resistance of metal wire would be equal to 7.96×10⁻³Ω.

Explanation:

Given: The resistivity of the wire, $\rho =5*10^{-8}m$

Length of wire, $L=2m$

Radius of the wire $r=2mm=2*10^{-3}m$

Cross section area of the wire :$A=\pi r^{2}= (3.14)(2*10^{-3})^{2}=12.56*10^{-6}m^{2}$

Resistance, $R=(\frac{\rho L}{A})$

$R=\frac{((5*10^{-8}(ohm)m)(2m)}{12.56*10^{-6}m^{2}}$

$R=0.796*10^{-2}$Ω

$R=7.96*10^{-3}$Ω

Therefore the resistance for the given wire will be equal to 7.96×10⁻³Ω