Please explain the answer to the question.. "resistance of a metal wire of length 1 m is 26 ohm at 20°C. If the diameter of the wire is 0.3 mm, what will be the resistivity of the metal at that temperature?"
Answers
Answered by
0
hello,
given that length(L) of wire is 1m,diameter is 0.3mm=3×10⁻⁴m
and hence the area of cross-section will be πr² = 3.14×(3×10⁻⁴)²m²
=9.42×10⁻⁸m²(A)
temperature is constant,therefore no change in resistivity
resistance is 26Ω(R)
R=ρL/A
∴26=ρ1/9.42×10⁻⁸
=26×9.42×10⁻⁸=ρ
ρ=2.4492×10⁻⁶Ωm
therefore resistivity of the wire at that temperature only is 2.4492×10⁻⁶Ωm
hope this helps
given that length(L) of wire is 1m,diameter is 0.3mm=3×10⁻⁴m
and hence the area of cross-section will be πr² = 3.14×(3×10⁻⁴)²m²
=9.42×10⁻⁸m²(A)
temperature is constant,therefore no change in resistivity
resistance is 26Ω(R)
R=ρL/A
∴26=ρ1/9.42×10⁻⁸
=26×9.42×10⁻⁸=ρ
ρ=2.4492×10⁻⁶Ωm
therefore resistivity of the wire at that temperature only is 2.4492×10⁻⁶Ωm
hope this helps
Similar questions