Answer:
Resistance of wire, R = 1.5 ohm
Explanation:
Given that,
The resistivity of the platinoid wire, ρ = 3.3 x 10⁻⁷ ohm - meter
Length of the platinoid wire, l = 7 meter
Diameter of the wire, d = 0.14 cm = 0.0014 m
Radius of the wire, r = d/2 = 7 x 10⁻⁴ m
Therefore, core sectional area of the wire, A = π r²
= 1.539 x 10⁻⁶ m²
According to Pouillet's law, the resistance of a wire is given by the relation,
R = ρ · l/A ohm
Substituting the values in the above equation
R = 3.3 x 10⁻⁷ [tex]\frac{7}{1.539 X 10^{-6}}[/tex]
= 1.5 ohm
Hence, the resistance of the given platinoid wire is, R = 1.5 ohm
