Question

What will be the resistivity of a metal wire of 3m length and 0.8mm in diameter, if the resistance of the wire is 60ohm

Answer 1

Answer:

Resistance (R) = 50 Ω

Length of the wire ( l ) = 2 m

Diameter of the wire = 0.6 mm

Radius = 0.6 / 2 = 0.3 mm

= 3 × 10^-4 m

Resistivity ( ρ ) = ?

Area of cross sectional area of wire (A) = πr^2

= 3.14 ×( 3 × 10^-4)^2

= 2.826 × 10^9 m^2

We know,

ρ = RA / l

ρ = 50 × 2.826 × 10^-9 / 2

ρ = 25 × 2.826 × 10^-9

ρ = 70.65 × 10^-9 or 7.065 × 10^-8 Ω m

Resistivity of the wire is 7.065 × 10^-8 Ω m.

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