Caculate the resisticity of the material of wire 1.0 m long 0.4 mm in diameter and having resistance of 2.0 ohm .

Explanation

Resistivity `(rho)=?`
Length (l) =1.0 m
Diameter = 0.4 mm
Radius of wire `=r=(0.4)/(2)rArrr=(cancel4^(cancel2^(1)))/(5^(cancel10xxcancel2))`
`r=(1)/(5)rArr=0.2` mm
`r=0.2xx10^(-3)m rArrr=(2)/(10)xx10^(-3)` m
`r=2xx10^(-3-1)mrArrr=2xx10^(-4)m`
Resistance `=R=2.0Omega`
`R=rho(l)/(A)`
`rho=(RA)/(L)`
`rho=(R)/(l)(pir^(2))`
`rho=(2)/(1)xx(22)/(7)xx(2xx10^(-4))^(2)`
`rho25.14xx10^(-8)`
`rho=2.514xx10^(-7)Omegam`