Question

12. The resistivity of a given wire of cross-sectional

area 0.7mm 4.9 x 10raised to the power of -4ohm mm. Calculate the
resistance of a 2ohm length of the wire​

Answer 1

R = resistivity × (l/A), A = πr^2= πd^2/4

2 =( 4.9 × 10^ -4) * (l/π0.7^2/4)

make l the subject and calculate.

i assumed we are looking for the length if the wire.