Question

Calculate the resistance of a metal wire of length 2m and area of cross section 1.55x106m2, if the resistivity of the metal be 2.8x10-8Ωm?

Answer 1

Correct Question :

Calculate the resistance of a metal wire of length 2m and area of cross section 1.55x10^(-6)m², If the resistivity of the metal be 2.8x10-8Ωm.

Given :

• Resistivityc= 2.8x10-8Ωm.
• Area of Cross Section = 1.55x10^(-6)m²
• Length of Wire = 2m.

Solution :

We have, Formula.

$\tt \dagger \: \: \: \: \: R = \rho \dfrac{ L}{ A}$

Where as,

• R - Resistance of Wire.
• Rho - Resistivity.
• A - Cross section Area of Wire.

$\tt\longmapsto R = \dfrac{ 2.8 \times {10}^{ - 8} \times 2}{ 1.55 \times {10}^{ - 6} }$

$\tt\longmapsto R = \dfrac{ 2.8 \times {10}^{ \cancel{- 8}} \times 2}{ 1.55 \times {10}^{ \cancel{- 6}} }$

$\tt\longmapsto R = \dfrac{ 2.8 \times {10}^{ - 2} \times 2}{ 1.55 \times }$

$\tt\longmapsto R =2.8 \times { 10}^{ - 2} \times 1.290.$

$\tt\longmapsto R =3.612 \times {10}^{ - 2} \: \Omega.$

$\tt\longmapsto R =0.03612 \: \Omega.$

Therefore, the value of Resistance is 0.03612Ω.