Respuesta :
given:
Length, l=1 km=1000 m
Radius, r=1 mm=10^−3 m
to find:
the resistance.
solution:
Specific resistance of copper:
ρ=1.72×10^−8
Area of cross-section:
A=π×r2=3.14×10^−6 m^2
Let the resistance be R.
As we know, R=ρ l/A
On substituting values:
R=1.72×10^−8×10^3/3.14×10^−6
=5.5 ohm
⇒ Resistance of the copper wire, is 5.5 ohm.
5.5 Ω
Explanation:
Given : l = 1 km = 1000 m, r = 1 mm = 10^-3 m,
[tex]a = \pi {r}^{2} [/tex]
[tex]= > 3.14 \times ( {10}^{ - 3} )^{2} \\ = > 3.14 \times {10}^{ - 6} \: {m}^{2} .[/tex]
[tex]specific \: \: resistance \: \: ρ \: \\ = > 1.72 \times {10}^{ - 8} Ω \: m[/tex]
Resistance (R) :-
[tex]R \: = ρ \times \frac{l}{a} \\ \\ = > \frac{(1.72 \times {10}^{ - 8} ) \times 1000}{3.14 \times {10}^{ - 6} } \\ \\ = > 5.5 \: Ω[/tex]
