Question

The resistance of a wire of 0.01 cm radius is 10Ω. If the resistivity of the material of the

wire is 50*10-8Ω.m, find the length of the wir​

Answer 1

Correct Question:

The resistance of a wire of 10Ω radius is 0.01cm. If the resistivity of the material of the wire is 50 × 10^{-8} Ωm, find the length of the wire.

Given:

• Resistance of a wire (R) = 10Ω
• Radius (r) = 0.01 cm ⇒0.0001 m
• Resistivity of the material of the wire (ρ) = 50 × 10^{-8}Ωm

To Find:

• The length of the wire.

Solution:

We know that,

R = ρl/A

[ Put the values ]

⇒ 10 = 50 × 10^{-8} × l / 3.14 × (0.0001)²

⇒ 10 = 50 × 10^{-8} × l / 157/50 × 10^{-8}

⇒ 10 = 50 × l / 157/50

⇒ 10 = 2500 × l / 157

⇒ l = 157/200

⇒ l = 0.628 m

Hence,

The length of the wire is 0.628 m.