Question

Find the resistance of wire of0.65m Radius 0.25andresistivity 3x10-6 OHM​

Answer 1

Complete Question:

Find the resistance of a wire of length 0.65 m, radius 0.25 mm and resistivity 3 * 10^{-6} ohm-metre.

Answer:

Resistance = 9.95 Ohms

Explanation:

Given the following data;

Length = 0.65 m

Radius = 0.25 mm to meters = 0.00025 m

Resistivity = 3 * 10^{-6} ohm-metre.

To find the resistance of the wire;

Mathematically, resistance is given by the formula;

$Resistance = P \frac {L}{A}$

Where;

• P is the resistivity of the material.
• L is the length of the material.
• A is the cross-sectional area of the material.

First of all, we would find the cross-sectional area of the wire.

Area of circle = πr²

Substituting into the equation, we have;

Area  = 3.142 * (0.00025)²

Area = 3.142 * 6.25 * 10^{-8}

Area = 1.96 * 10^{-7} m²

Now, to find the resistance of the wire;

$Resistance = 3 * 10^{-6} * \frac {0.65}{1.96 * 10^{-7}}$

$Resistance = 3 * 10^{-6} * 3316326.531$

Resistance = 9.95 Ohms