Question

Calculate the resistance of 1km long copper wire of radius 1mm.resistivity of the copper wire is 1.72×10power -8

Answer 1

1 km = 1*10^3
1 mm= 1*10^-3
rho = 1.72*10^-8
A = PI r^2

now    R = rho l/A

APPLY THIS .. TO GET THE ANSWER

Answer 2

GIVEN THAT

• Length of copper wire = 1 km = 1000 m
• Radius of copper wire = 1 mm = 1 × 10-³ m
• Resistivity of copper = 1.72 x 10⁻⁸

CALCULATION OF RESISTANCE

• (Resistivity of copper × Length)/(Area)
• (Resistivity of copper × Length)/(πr²)
• [1.72×10⁻⁸*1000]/[22/7×(1×10⁻³)²]
• 5.5 ohm