Question

The resistance of a uniform copper wire 50.0 meters long and 1.15 mm in diameter is 0.830 ohms at 20° C. What is the resistivity of the copper at this temperature?

Answer 1

Answer:

R=pl/A

R=0.830

A=1.04×10power-6

p=?

so,

p=RA/l

=0.830×1.04×10power -6/50

p=1.72×10power-8

Explanation:

This is the answer ...

Answer 2

Answer:

The resistivity, ρ, of the copper wire calculated is $1.66\times 10^{-8}\Omega-m$.

Explanation:

Data given,

The length of a uniform copper wire, L = $50m$

The diameter, d = $1.15mm$ = $1.15 \times 10^{-3}m$

The resistance of the wire, R = $0.830\Omega$

The copper wire's resistivity, $\rho$ =?

As we know,

• Resistivity, $\rho$ = $\frac{RA}{L}$    -------equation (1)

Here, A = area of the wire = $\pi r^{2}$

Now,

• Radius = $\frac{d}{2}$ = $\frac{1.15 \times 10^{-3}}{2}$ = $0.57\times 10^{-3} m$
• A = $\pi r^{2}$ = $3.14\times (0.57\times 10^{-3})^{2}$ = $3.14\times 0.32\times 10^{-6}$ = $10^{-6}m^{2}$.

After putting the values of the area, resistance, and length in equation (1), we get:

• Resistivity, $\rho$ = $\frac{0.830\times 10^{-6} }{50}$ = $1.66\times 10^{-8}\Omega-m$

Hence, the resistivity of the wire calculated is $1.66\times 10^{-8}\Omega-m$.