The folllowing reading are obtained in a meter bridge experiment to find the resistivity of the material of a given wire. Calculate the resistivity of the material of the wire.
Diameter of the wire `=d =0.36 mm, ` length of the wire `L = 60 cm.`

Explanation

Tr 1. `R _(1)=(Sl _(1))/( 1 - l _(1)) = ( 3 xx 0. 59 )/( 0.41) = 4.32 Omega`
Tr 2. `R _(2) = ( Sl _(2))/( 1 - l _(2)) = ( 6 xx 0. 43 )/( 0. 57 ) = 4. 52 Omega `
Now : ` (##OSW_SP_PHY_XII_C03_E02_011_S01.png" width="80%">
`R _(av) = 4.42 Omega`
`rho = ( pi d ^(2) R _(av ))/( 4 L )` A
`rho = ( 3. 14 xx 4. 4 2 xx ( 0. 36 xx 10 ^(-3)^(2)))/( 4 xx 0.6)`
`rho = 0. 748 xx 10 ^(-6) Omega -m`