The resistivity of the material of a wire of length 1 and diameter d and resistance R is given by `rho=(piRd^(2))/(4l)`. The length of the wire I=100.0 cm is measured using a metre scale with a least count of I mm, the diameter d=0.22 cm is measured using an instrument with a least count of 0.01 cm and resistnce R=5.00 ohm is measured with an accuracy of 0.01 ohm. What is the percentage error? Suggest a method to reduced the percentage error.

Explanation

`rho=((piRd^(2))/(4l))`
`:.` Percentage error `rho=(Deltarho)/(rho)xx100-(DeltaR)/Rxx100+2(Deltad)/d xx100+(Deltal)/lxx100`
`=0.01/5.00xx100+2xx0.01/0.22xx100+0.1/100xx100=9.3%`